Honeywell Home Safety Product R4795A User Manual

R4795A  
Flame Safeguard  
Primary Controls  
The R4795A Protectorelay™ Primary Control  
provides solid state electronic flame safeguard  
protection for commercial and industrial gas or oil  
burners. It provides a prepurge period before each  
start, and intermittent pilot.  
Solid state circuitry eliminates vacuum tube replace-  
ment and increases resistance to vibration. Applica-  
tion of power not required during Off cycle; no tube  
warmup before starting.  
Easy-to-replace plug-in components result in faster  
service and reduced inventory.  
Flame current jack, located on the amplifier, provides  
means of plugging in a microammeter to measure the  
flame signal with system operating.  
Easy mounting and removal through use of captive  
mounting screws, which also serve as electrical  
connections.  
120V models meet the requirements of Underwrit-  
ers Laboratories Inc. Standard 795 for mechanical  
draft and atmospheric burner inputs from 400,000 to  
2,500,000 Btu.  
Meets Underwriters Laboratories Inc. requirements  
for oil burner group 8 when 30, 60, or 90 second pre-  
purge timer is used.  
Selection of solid state, plug-in prepurge timers pro-  
vides 7, 10, 30, 60, or 90 second prepurge time.  
Includes terminals for connection of air flow switch  
to prove airflow before prepurge period starts, dur-  
ing purge, and during the entire Run period.  
Choice of interchangeable, color-coded, solid state,  
plug-in flame signal amplifiers allows use with rec-  
tification or ultraviolet type flame detectors.  
Safe-start feature prevents start when flame or flame  
simulating condition is present.  
Durable thermoplastic mounting base.  
Models available with -40°F (-40°C) temperature  
rating.  
Recycles through prepurge if the flame goes out  
while burner is running. If pilot flame is not re-  
established, safety switch trips and locks out system.  
A tripped safety switch must be manually reset to  
restore operation.  
Push-to-resetsafetyswitchisdust-resistantenclosed.  
Optional spdt alarm contacts operate external alarm  
on safety switch lockout.  
Ignition interference circuit (rectification amplifier  
only) protects electronic network from high voltage  
ignition crossover and provides visual indication  
when interference occurs.  
CONTENTS  
Specifications ................................................. 2  
Ordering Information ..................................... 2  
Installation ..................................................... 4  
Checkout......................................................... 8  
Operation ..................................................... 11  
Troubleshooting ........................................... 11  
Service .......................................................... 13  
S.Y. • Rev. 12-94 • ©Honeywell Inc. 1994  
60-2285-7  
 
R4795A  
SPECIFICATIONS  
TERMINAL RATINGS:  
Terminal  
Load  
Rating  
3
Pilot Valve  
125 VA pilot duty.  
a
Intermittent Ignition 360 VA.  
Interrupted Ignition 360 VA.  
4
5
Main Fuel Valve(s) 125 VA pilot duty, or 25 VA pilot duty plus one or more motorized  
valves with total rating up to 400 VA opening, 200 VA holding.  
6-7  
8
Airflow Switch  
0.6A at 30 Vdc.  
Fan or Burner Motor 9.8A full load, 58.8A locked rotor (inrush) at 120 Vac. 4.9A full  
load, 29.4A locked rotor (inrush at 220 and 240 Vac.  
Isolated Spdt Alarm  
Terminals (Optional)  
Alarm  
3A at 24 volts, or 1A at 120 volts, in a suitable wiring enclosure.  
a When ignition is connected to terminal 3, terminal 4 cannot be used.  
NOTE: Allowable inrush can be up to ten times the pilot  
duty rating.  
118702E Remote Reset Cover, 120 Vac, 60 Hz  
202471C Reset Cover for R4795A  
ADDITIONAL CONTROLS:  
Example:  
Pilot duty rating = 125 VA.  
Order all additional controls separately:  
Q270A1024 Mounting Subbase.  
At 120V, running current is 125/120 = 1.05A.  
Maximum allowable inrush is 10 times 1.05 = 10.5A.  
Plug-In Flame Signal Amplifiers, Rectification Type  
(Green Backplate): For use with C7004B C7005A,  
and B, C7008A, or Q179A,C Rectifying Flame Rods  
(for gas); C7003A, C7010A, C7013A or C7014A  
Photocells (for oil); or C7012A,C Purple Peeper Ul-  
traviolet Flame Detectors (for gas or oil).  
R7289A1004 Amplifier: 3 sec nominal flame failure  
response.  
R7289A1012 Amplifier: 0.8 sec nominal flame failure  
response.  
R7289A1020 Amplifier: 3 sec nominal flame failure  
response, -40°F (-40°C) ambient temperature.  
UltravioletType(PurpleBackplate):ForusewithC7027A,  
C7035A or C7044A Minipeeper Ultraviolet Flame  
Detectors (for gas or oil).  
DIMENSIONS (Includes Cover and Subbase): Approxi-  
mately 5 x 5 x 5 in. (127 x 127 x 127 mm).  
MOUNTING: Q270A1024 Subbase. Ordered separately.  
APPROVALS:  
Underwriters Laboratories Inc Listed: 120V models us-  
ing 30, 60, or 90 second prepurge timers including –  
40°F (–40°C) rated models; file no. MP268, guide  
no. MCCZ.  
Underwriters Laboratories Inc. Component Recognized:  
120 volt models using 7 or 10 second prepurge timers  
including-40°F(-40°C)ratedmodels;fileno. MP268,  
guide no. MCCZ2.  
Canadian Standards Association Certified: 120V mod-  
els only, including -40°F (-40°C) rated models; file  
no. LR95329.  
Factory Mutual Approved: R4795A 120V models; re-  
port no. 18774. -40°F (-40°C) rated models; report  
no. 19608.1.  
R7290A1001 Amplifier: 3 sec nominal flame failure  
response.  
R7290A1019 Amplifier: 0.8 sec nominal flame failure  
response.  
R7290A1027 Amplifier: 3 sec nominal flame failure  
response, -40°F (-40°C) ambient temperature.  
ST71A Plug-In Prepurge Timer (ordered separately):  
Minimum Timings: 7, 10, 30, 60, and 90 seconds (as  
ordered).  
American Gas Association Design Certified: File no. 21-6  
(F and F1).  
ACCESSORIES:  
W136A Test Meter (includes 117053 Meter Connector  
Plug).  
Flame Simulator:  
Maximum Timings: 8.4, 12, 36, 72, and 108 seconds  
at room ambient temperature.  
RecommendedLimits:L404A;L604A,L;L4006A,C,E;  
L4008A,E,F; L6006A,B: These controllers were  
Underwriters Laboratories Inc. tested for breaking  
loads only, at 120 Vac, for the total rating of 9.8A  
full load, plus 360VA ignition, plus 250 VA pilot  
duty.  
203659 Ultraviolet  
121708 Rectification  
123514B Ultraviolet  
117053 Meter Connector Plug  
FSP1535 Tester for operational check  
Q624 Solid State Spark Generator  
Flame Detector: As specified in Plug-In Flame Signal  
Amplifiers listed above.  
3
60-2285—7  
 
R4795A  
INSTALLATION  
Installation  
Vibration  
CAUTION  
Do not install the R4795A where it could be subject to  
excessive vibration. Vibration shortens the life of the elec-  
tronic and mechanical components.  
1. Installer must be a trained, experienced, flame  
safeguard control service technician.  
2. Disconnect power supply before beginning in-  
stallation to prevent electrical shock and equip-  
ment damage.  
Weather  
The R4795A is not designed to be weathertight. If it is  
installed outdoors, use a suitable weathertight enclosure.  
3. All wiring must comply with applicable local  
electrical codes, ordinances, and regulations.  
4. Voltage and frequency of the power supply  
connected to this control must agree with those  
marked on the device.  
5. Loads connected to the control terminals must  
not exceed those listed in the Specifications  
section.  
6. All external timers must be Listed or Compo-  
nent Recognized by authorities having jurisdic-  
tion for the specific purpose for which they are  
used.  
7. Some authorities having jurisdiction prohibit  
the wiring of any limit or operating contacts in  
series with the main fuel valve(s).  
Mounting The Subbase  
Locate the subbase where ambient temperature is within  
the specified rating.  
Mount the subbase so the top and bottom are horizontal  
and the back is vertical. The subbase can lean backward as  
much as 45 degrees when necessary. See Fig. 1.  
Fig. 1—Subbase mounting dimensions in in.  
(mm).  
VERTICAL  
HORIZONTAL  
45 DEGREES  
MAXIMUM LEAN  
8. Perform all required checkout tests after instal-  
lation is complete.  
Follow the burner manufacturer’s instructions, if sup-  
plied. Otherwise proceed as follows.  
2-7/8  
(73.0)  
CAUTION  
Ultraviolet sensing tubes have a life expectancy of  
40,000 hours of continuous use within the ambient  
temperature and voltage ratings. Worn out ultra-  
violet sensing tubes can result in failure of the  
sensingtubetoproperlydiscriminatebetweenflame  
conditions.  
4-1/8 (104.8)  
KNOCKOUTS (9) FOR  
1/2 IN. (13) CONDUIT  
M8681  
WIRING TO SUBBASE  
1. All wiring must comply with applicable codes, ordi-  
nances, and regulations. All wiring to the Q270A Universal  
Mounting subbase must be NEC Class 1.  
2. When wiring the Q270A for use with the R4795A, use  
the terminal designations 8, 7, and 6 (printed in yellow).  
3. For normal installations, use moisture-resistant No. 14  
wire suitable for at least 167°F (75°C).  
For systems using R4795A with R7290 Amplifiers, use  
C7027, C7035 and C7044 Flame Detectors only on burners  
that cycle On and Off at least once every 24 hours. Appli-  
ances with burners that remain on for 24 hours continuously  
or longer should use the C7012E Flame Detector with the  
R7247C Amplifier or the C7076A Flame Detector with the  
R7476A Amplifier as the ultraviolet flame detection system.  
4. For high temperature installations, use moisture-re-  
sistant No. 14 wire selected for a temperature rating above  
the maximum operating temperature for all but the ignition  
and flame detector F leadwires.  
LOCATION  
Temperature  
Install the R4795A where the surrounding temperatures  
remain within the Ambient Operating Temperature Ratings  
listed in the Specifications section.  
a. For the ignition, use Honeywell Specification no.  
R1061012 Ignition Cable or equivalent. This wire is  
rated at 350°F (175°C) for continuous duty, and up to  
500°F (260°C) for intermittent use.  
Humidity  
b. For the flame detector F leadwire, use Honeywell  
Specification no. R1298020 or equivalent. This wire  
is rated up to 400°F (205°C) for continuous duty. It is  
tested for operation up to 600V and breakdown up  
to 7500V.  
Install the R4795A where the relative humidity never  
reaches the saturation point. Condensation of moisture on  
the R4795A may cause enough leakage to short the flame  
signal to ground and prevent the burner from starting.  
60-2285—7  
4
 
R4795A  
INSTALLATION  
IMPORTANT: Do not run high voltage ignition trans-  
former wires in the same conduit with the flame  
detector wiring.  
Fig. 3—Wiring hookup of oil system with  
interrupted ignition.  
5. For ignition installations in a contaminating environ-  
ment, use Honeywell Specification no. R1239001 High Ten-  
sion Ignition Cable or equivalent. This wire is very resistant  
to severe conditions of oil, heat, and corona, and is tested to  
withstand high voltages up to 25,000V rms in a salt bath for  
one minute without breakdown. It is rated at 200°F (93°C)  
for continuous duty and up to 350°F (75°C) for intermittent  
use.  
4
2
3
2ND STAGE  
OIL VALVE(S)  
5
4
BURNER  
MOTOR  
8
2K3  
2K2  
AIR FLOW  
SWITCH  
IGNITION  
7
1ST STAGE  
OIL VALVE(S)  
6
3
1K4  
3K2  
Wiring Hookups  
The typical wiring hookups in Fig. 2 and 3 show the  
internallinevoltageschematic. Contact3K2closeswhenthe  
controller calls for heat. 1K4 closes when prepurge is com-  
plete. 2K2 breaks and 2K3 makes when flame is proven.  
Also see the Operation section.  
F
TO FLAME  
DETECTOR  
(PHOTOCELL  
OR UV)  
FLAME  
AMPLIFIER  
G
1
CONTROLLER  
LIMIT(S)  
2
5
Fig. 2—Wiring hookup of gas system with  
interrupted ignition and intermittent pilot.  
R4795A  
1
L1  
(HOT)  
MAIN FUEL  
VALVE(S)  
L2  
5
BURNER  
MOTOR  
8
2K3  
2K2  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
2
AIR FLOW  
SWITCH  
4
IGNITION  
2
3
4
FOR INTERMITTENT IGNITION,CONNECT IGNITION TO TERMINAL 3.  
IMMEDIATE OPENING OIL VALVE V4046B.  
7
PILOT  
VALVE  
OPTIONAL DELAYED OPENING OIL VALVE V4046A OR V4046B WITH  
ST70A ELECTRONIC TIME DELAY.  
6
3
1K4  
3K2  
5
REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.  
M8683  
F
TO FLAME  
DETECTOR  
(FLAME ROD  
OR UV  
FLAME  
AMPLIFIER  
G
1
Retrofitting R4795  
DETECTOR)  
CONTROLLER  
LIMIT(S)  
2
CAUTION  
3
Make wiring connections as specified in Fig. 2, 3,  
or 4. Do not simply plug the R4795 into the old  
subbase without first changing the wiring at the  
subbase.  
R4795A  
1
L1  
(HOT)  
L2  
Observe the following when retrofitting the R4795:  
1. Requiresalinevoltagecontrollercapableofswitching  
the entire connected electrical load.  
2. Delayed opening oil valve may be retained but its  
delay is not necessary. Integral ST71A Purge Timer meets  
the intent of a delayed opening valve.  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
2
3
FOR INTERMITTENT IGNITION, CONNECT IGNITION TO TERMINAL 3.  
REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.  
M8682  
3. Refer to Fig. 2, 3 or 4 for proper wiring connections.  
5
60-2285—7  
 
R4795A  
INSTALLATION  
Replacing RA890E,F,G with R4795A  
R4795C Replacement  
1. Disconnect all wires from terminal 1, and splice with  
solderless connector. (If RA890 has no terminal 1 wiring,  
disregard this step.)  
In most cases, the R4795A can directly replace the  
R4795C. For standing pilot applications where the pilot  
flame was detected during the off cycle, install a relay as  
shown in Fig. 5.  
2. Remove line voltage controller wire from terminal 6  
and connect to terminal 1.  
3. Move burner motor connection from terminal 3 to ter-  
minal 6 on subbase.  
Flame Detector Wiring  
See Fig. 6.  
4. Remove jumper from T and T and install air switch. If  
low voltage control was wired to RA890 T-T, remove low  
voltage control and install line voltage control as shown in  
Fig. 4.  
5. If R482D Relay was used with RA890E, remove it.  
The R482D is redundant when R4795D is used.  
Alarm Contacts  
Models with alarm contacts have three male quick-con-  
nect terminals. Three female quick-connect terminals are  
provided for field installation. To connect leadwires to the  
female quick-connects, strip 1/4 inch (6.4 mm) insulation  
from end of leadwire; insert into the quick-connect, and  
crimp securely with a crimping tool. Fig. 7 shows proper  
alarm terminal connections.  
6. Checkforproperoperationthroughatleasttwocycles.  
If a line voltage alarm is used with the R4795, mount the  
entire control in a suitable enclosure.  
Fig. 4—Replacing RA890E,F,G with R4795A on  
gas or oil burner.  
REPLACING RA890 WITH R4795 ON GAS OR OIL BURNER  
Fig. 5—When R4795A replaces R4795C in a  
standing pilot application, install relay 1R to  
prevent detection of pilot flame during burner  
off cycle.  
BEFORE  
CONTROLLER  
HIGH LIMIT  
MAIN GAS  
VALVE OR  
2ND STAGE  
OIL VALVE  
6
T
T
F
5
4
3
IGNITION  
TRANSFORMER  
MIAN FUEL  
VALVES  
5
4
BURNER  
MOTOR  
8
2K3  
2K2  
BURNER  
MOTOR  
PILOT OR  
OIL VALVE  
7
FLAME  
DETECTOR  
L1  
(HOT)  
3
1
2
1R  
AIR FLOW  
SWITCH  
1K4  
3K2  
120V  
6
F
G
L2  
1R1  
RA890 WITH Q270  
TO FLAME  
DETECTOR  
FLAME  
AMPLIFIER  
AFTER  
G
CONTROLLER  
HIGH LIMIT  
(FLAME ROD  
OR UV  
DETECTOR)  
MAIN GAS  
VALVE OR  
2ND STAGE  
OIL VALVE  
1
CONTROLLER  
LIMIT(S)  
3
2
6
T
T
F
8
7
6
5
4
2
IGNITION  
TRANSFORMER  
AIR FLOW  
SWITCH  
R4795A  
BURNER  
MOTOR  
3
1
L1  
L2  
PILOT OR  
OIL VALVE  
SODERLESS  
CONNECTION  
(HOT)  
FLAME  
DETECTOR  
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD  
PROTECTION AS REQUIRED.  
L1  
(HOT)  
1
2
G
120V  
2
3
REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.  
LOW VOLTAGE CIRCUIT OMITTED.  
M8685  
L2  
RA4795 WITH Q270  
M8684  
60-2285—7  
6
 
R4795A  
INSTALLATION  
Fig. 6—Flame detector wiring.  
Fig. 7—Alarm terminal connections.  
PHOTOCELL  
FLAME ROD  
F
X
X
F
X
X
G
G
ALARM TERMINALS (OPTIONAL)  
R4795  
C7012 ULTRAVIOLET DETECTOR  
N.O.  
COM  
N.C.  
L1  
(HOT)  
ALARM  
2
POWER  
SUPPLY  
LINE OR  
LOW VOLTAGE  
L2  
ALARM  
1
IF A LINE VOLTAGE ALARM IS USED, THE R4795 MUST BE  
MOUNTED IN A SUITABLE ENCLOSURE.  
1
2
BLUE  
F
X
YELLOW  
G
X
POWER SUPPLY MUST MATCH THE ELECTRICAL RATINGS OF THE  
ALARM. PROVIDE DISCONNECT MEANS AND OVERLOAD  
BLACK  
BLACK  
PROTECTION AS REQUIRED.  
M8687  
POWER  
SUPPLY  
1
C7027, C7035, OR C7044  
CAUTION  
ULTRAVIOLET FLAME DETECTOR  
BLUE  
F
X
X
Do not overtighten the mounting screws because  
damage to the circuit board can result. Maximum  
recommended torque is 10 lb-in. (1.13 N•m).  
WHITE  
G
C7027, C7035, AND C7044 FLAME DETECTOR LEADS ARE COLOR  
1
CODED BLUE AND WHITE. THE BLUE LEAD MUST BE CONNECTED  
TO THE F TERMINAL AND THE WHITE LEAD MUST BE CONNECTED  
TO THE G TERMINAL. THIS CIRCUIT IS DC AND THE UV SENSING  
TUBE IS POLARITY SENSITIVE. REVERSING THE LEADS EVEN  
MOMENTARILY CAN DAMAGE OR DESTROY THE UV TUBE.  
Replace cover and securely tighten thumbscrew.  
M8686  
Fig. 8—R4795 and Q270 Subbase.  
CAPTIVE MOUNTING  
SCREWS (10)  
Q270  
SUBBASE  
Mounting R4795 On Subbase  
SAFETY SWITCH  
RESET BUTTON  
IN COVER  
Make sure that the power supply is disconnected.  
Loosen the thumbscrew and remove the cover (see Fig. 8).  
Position the R4795 over the Q270 Subbase. Start all ten  
mounting screws and tighten uniformly. These screws com-  
plete electrical circuits (terminal 1 excepted) and hold the  
R4795 to the subbase.  
TERMINAL  
BLOCKS  
COVER  
AMPLIFIER  
THUMBSCREW  
M8688  
PURGE TIMER  
7
60-2285—7  
 
R4795A  
CHECKOUT  
Checkout  
Fig. 10—Internal view showing amplifier and  
CAUTION  
test jack for flame current test.  
Use extreme care while testing the R4795; line  
voltage can be present on most terminals when the  
power is On.  
ARC-GAP IGNITION INTERFERENCE  
PROTECTION (R7289 RECTIFICATION  
AMPLIFIER ONLY)  
ST71A  
TEST JACK  
PLUG-IN  
PURGE  
TIMER  
CHECKOUT SUMMARY  
The following list summarizes the checkout tests re-  
quired for each type of installation. Instructions for each test  
are included in this section.  
PLUG-IN  
AMPLIFIER  
Preliminary Inspection: All installations.  
Flame Current Check: All installations.  
Pilot Turndown Test: If a pilot must be proved before the  
main fuel valves can open.  
Hot Refractory Hold-in Test: Photocell oil installations  
only.  
AMPLIFIER  
CONNECTORS  
PURGE TIMER  
CONNECTORS  
OPTIONAL  
ALARM TERMINALS  
Ignition Spark Response Test: All ultraviolet detector  
applications.  
M8680  
Safe Shutdown Tests: All installations.  
Refer to Fig. 2 to 3 for terminal location, and to Fig. 9 and  
10 for location of component parts. Loosen thumbscrew to  
remove cover.  
PRELIMINARY INSPECTION  
Make certain that:  
1. Wiringconnectionsarecorrectandallterminalscrews  
are tight. Use a meter to check the continuity of all circuits.  
2. Flame detector is installed and positioned properly.  
Consult the appropriate installation instructions.  
3. Ambient temperature at flame detector does not ex-  
ceed maximum rated temperature.  
4. Correctcombinationofamplifierandflamedetectoris  
used. Refer to Plug-In Flame Signal Amplifiers in Specifica-  
tions section.  
5. Burner is completely installed and ready to fire; fuel  
lines are purged of air.  
6. Combustion chamber and flues are clear of fuel.  
7. Power is connected to system disconnect switch (mas-  
ter switch).  
Fig. 9—Internal components of R4795A.  
2K  
3K  
CAPTIVE  
MOUNTING  
SCREWS  
(10)  
1K  
UNDER  
COVER  
PLUG-IN  
PURGE  
TIMER  
SAFETY  
SWITCH  
RESET  
(ST71A)  
BUTTON  
8. Safety switch is reset; push in and then release the  
green safety switch.  
9. All limits and interlocks are reset.  
SPRING  
CLIP FOR  
AMPLIFER  
IMPORTANT: Anytime you reset the safety switch, wait at  
leastoneminuteafterittripstoallowtheheatertocool  
before pushing in the reset button.  
TRANSFORMER  
PLUG IN AMPLIFIER  
(R7289–GREEN–RECTIFICATION)  
(R7290–PURPLE–ULTRAVIOLET)  
M8679  
CAUTION  
Make initial pilot lightoff with manual main fuel  
shutoff cock closed.  
60-2285—7  
8
 
R4795A  
CHECKOUT  
FLAME CURRENT CHECK  
2. The flame current is at least two microamperes for  
The flame current check is the best indicator of proper  
flame detector application. Perform the check at the time of  
installation, and at any time service is done on the system,  
and at least once a month, or more often, while the system is  
in operation. This prevents shutdowns due to poor flame  
signal.  
R7289A Rectification Amplifier (color-coded green), or at  
least1.5microamperesforanR7290AUltravioletAmplifier  
(color-coded violet).  
IF A STEADY READING OF AT LEAST MINIMUM  
STRENGTH CANNOT BE OBTAINED, ONE OR MORE  
OF THE FOLLOWING CONDITIONS CAN EXIST:  
• Improper supply voltage.  
Test by connecting a W136 (or equivalent) to the ampli-  
fier and reading the flame current while the burner is operat-  
ing. (Fig. 11).  
• Defective flame detector wiring including:  
— Open circuits.  
— Short circuits.  
Fig. 11—Connecting meter to read flame  
current.  
— High resistance shorts caused by moisture, accu-  
mulated dirt, or an improper choice of detector lead-  
wire for the particular installation.  
117053 METER  
CONNECTOR PLUG  
(SUPPLIED WITH W136)  
PLUG-IN  
AMPLIFIER  
• Impropersighting,improperviewingwindow,ordirty  
viewing window for optical detectors.  
• Improper application of a flame rod including:  
— Insufficient ground area.  
W136  
— Poor location of flame rod in flame.  
— Excessive heat on flame rod insulator, greater than  
600°F (316°C).  
FLAME  
CURRENT  
TEST JACK  
— Ignition interference.  
• Improper application of a vacuum photocell including:  
— Temperature over 165°F (74°C) at photocell.  
— Dirty photocell envelope.  
RED  
• Defective sensor.  
IF 117053 METER CONNECTOR PLUG IS NOT AVALIABLE  
(R7289A RECTIFICATION AMPLIFER ONLY)  
PILOT TURNDOWN TEST  
IMPORTANT: If the R4795 is used to prove a pilot flame,  
perform the following Turndown Test to assure that  
the main burner can be lit by the smallest pilot flame  
that will hold in the 2K (flame) relay.  
W136  
-
+
BLACK  
RED  
F LEAD  
G LEAD  
F
FLAME  
DETECTOR  
1. Shut off the fuel supply to the main burner only by  
closing the manual main burner shutoff cock. Do not shut off  
fuel supply to the pilot valve.  
G
R4795  
2. Start the system by raising the setpoint of the control-  
ler (or pressing the START button). After prepurge is com-  
pleted, the pilot will light and pull in the flame relay.  
3. Reduce the size of the pilot flame to the turndown  
conditionbyslowlyclosingthemanualvalveonthepilotgas  
line. At the turndown condition, the pilot will be small  
enough so it just barely holds in the flame relay (2K).  
a. Slowly turn down the pilot until the flame relay drops  
out.  
M8689  
Insert a 117053 Meter Connector Plug, wired color-to-  
color to the W136 leadwires, into the test jack on the ampli-  
fier (Fig. 10). This automatically puts the microammeter in  
series with the flame detector.  
If an R7289A Rectification Type Amplifier is used and a  
meter connector plug is not available, disconnect the flame  
detector lead from the F terminal; then connect this lead to  
the Black lead of the microammeter, and connect the Red  
lead of the microammeter to the F terminal.  
b. Allow the control to complete prepurge.  
c. As the control attempts to restart the pilot, turn the  
pilot back up slowly just until relay 2K pulls back in.  
You will have 15 seconds to complete this step before  
lockout occurs.  
d. Again turn the pilot down slightly but not enough so  
theflamerelaydropsout. Iftherelaydropsout, simply  
allow the control to complete the purge period and  
then turn the pilot back up to pull in the flame relay as  
in step c. above. The closer the pilot is to the dropout  
condition, the more conclusive the test will be.  
NOTE:IfanR7290AUltravioletTypeAmplifierisused, the  
flame current cannot be read by connecting a micro-  
ammeter in series with the F lead.  
When reading the flame current, assure that the following  
criteria are met:  
1. The flame current is steady; meter does not vary more  
than a needle width.  
9
60-2285—7  
 
R4795A  
CHECKOUT  
4. If relay 2K does pull in, resight the detector farther out  
from the spark, or away from possible reflection. It may be  
necessary to construct a barrier to block the ignition spark  
from the detector view. Continue adjustments until flame  
detector does not respond to the ignition spark.  
CAUTION  
Do not manually push in the relays.  
4. Check that the pilot is lit and relay 2K is pulled in.  
5. Open the manual main burner shutoff cock. Main  
flame should light within one second. If the burner does not  
light within one second, close the shutoff cock and shut off  
power to the relay. Proceed to step 7.  
6. If the burner lights, repeat step 5 two or three times to  
verify lightoff.  
IMPORTANT: Repeat ALL required checkout tests after all  
adjustments are complete. ALL tests must be satisfac-  
tory when the flame detector is in its FINAL position.  
SAFE SHUTDOWN CHECKS  
Limit Action  
With the burner operating, lower the high limit setting to  
simulate an overheated boiler or furnace. Normal shutdown  
should occur. Restore the normal limit setting; the burner  
should go through a normal prepurge and start.  
Using manual reset limits is desirable to prevent the  
system from cycling off the high limit and to assure that the  
condition that caused the limit action is detected as soon as  
possible.  
7. If the lightoff is unsatisfactory, readjust the flame  
detector to require a larger pilot flame to hold in the flame  
relay. This usually requires:  
a. Resighting a photocell or UV type detector farther  
out on the axis of a pilot flame, or  
b. Adjusting a flame rod detector so that a larger mini-  
mum pilot is required.  
8. Repeat the entire turndown test until the flame is  
established promptly in step 5.  
Flame Failure  
9. Turn up the pilot to full flame at the test completion.  
Let burner operate five minutes; then manually shut off  
fuel supply to simulate flame failure. Relay should drop out  
and fuel valve(s) close. The system will purge and then lock  
out on safety. Let the safety switch cool for one minute;  
reopen manual fuel valve, and reset safety switch. Burner  
should start.  
HOT REFRACTORY HOLD-IN TEST  
(PHOTOCELL OIL INSTALLATIONS ONLY)  
If hot refractory holds in the flame relay at the end of the  
burner-on cycle, the system cannot restart until the relay  
drops out. Check for hot refractory hold-in by observing the  
flame relay for immediate dropout at the end of a long  
burner-on period. If the relay does not drop out, resight the  
photocell so it does not sight the refractory, or decrease  
photocell sensitivity using aperture disks or filters.  
Power Failure  
Let the burner run five minutes. Then simulate power  
failure by opening the line switch. All relays should drop out  
and the fuel valves should close. After a minimum of five  
seconds, close the line switch. The R4795 should go through  
a normal cycle.  
IGNITION SPARK RESPONSE TEST  
(UV DETECTORS)  
The flame relay should not respond (pull in) to ignition  
spark. To determine flame detector sensitivity to ignition  
spark, perform the following test:  
1. Shut the pilot and main fuel manual valves.  
2. Start the system by raising the controller setpoint or  
pressing the START button. This should energize the igni-  
tion transformer so spark is produced between the electrode  
and ground.  
IMPORTANT: At the completion of all Checkout tests,  
make sure that the R4795 is not on safety lockout, that  
the pilot is turned up to its normal level, and that all  
limit settings are correct. Operate the system through  
one normal cycle. Replace cover and securely tighten  
thumbscrew.  
3. Checktheflamerelay2K. Therelayshouldnotpullin.  
The flame signal current should not be more than one-fourth  
microampere.  
60-2285—7  
10  
 
R4795A  
OPERATION • TROUBLESHOOTING  
Operation  
NORMAL OPERATION (REFER TO FIG. 2 AND 3.)  
Call for Heat (Limit Switch  
Closed)  
Terminal 1 energized. Relay 3K pulls in to close contact 3K2 and energize  
terminal 8 fan or burner motor.  
Airflow Proved  
Low voltage airflow switch between terminals 6 and 7 closes to energize the  
purge timer.  
Prepurge Complete (7, 10, 30, 60, Relay 1K pulls in to close contact 1K4 and energize terminal 3 (pilot valve, first  
or 90 Seconds)  
stage oil valve(s), or expanding pilot valve) directly and terminal 4 (ignition)  
through the closed flame relay contact 2K2. Contact 1K1 closes to energize the  
safety switch heater.  
Flame Proven (Pilot or First Stage R4795A: Relay 2K pulls in. Contact 2K2 opens to cut off ignition, contact 2K3  
Oil)  
closes to energize the main fuel valve(s) or second stage oil valve(s). Contact  
2K1 opens to de-energize the safety switch heater and reset the purge timer.  
Controller Satisfied  
All relays drop out; systems shuts down.  
SAFETY OPERATION  
Flame Failure  
R4795A: Relays 1K and 2K drop out. Contact 1K4 opens to de-energize  
terminals 3, 4, and 5. If air is still proven, the prepurge period begins. After  
prepurge, one attempt is made to start the burner.  
Airflow Failure  
If airflow fails at any time during the operating cycle, relay 1K drops out.  
Contact 1K4 opens to de-energize terminals 3, 4, and 5. Only terminal 8, fan or  
burner motor, remains powered. If air is re-established, the prepurge period  
starts and the startup sequence is repeated.  
Prepurge Timer Failure  
If the plug-in purge timer is not properly seated, or is not functioning properly,  
the fan motor will start on a call for heat, but the 1K relay will not pull in. The  
result will be a continuous purge (safe failure).  
Hot Refractory Hold-in (Photocell If hot refractory holds in the flame relay at the end of the running cycle, startup  
Installations) is prevented until the hot refractory no longer holds in the flame relay.  
Troubleshooting  
The first step in troubleshooting the R4795A is to deter-  
mine the location of the system trouble. Reset the safety  
switch and operate the system on a normal start. Refer to the  
Normal Operation subsection in the Operation section. Ob-  
serve the operation carefully to determine at what point the  
trouble occurs. Then refer to the Trouble List in the Trouble  
List section and follow the troubleshooting procedure.  
3. Reset the safety switch (push in and then release the  
small round button that extends through the plastic safety  
switch cover; see Fig. 9).  
TROUBLE LIST  
Compare the following list of troubles with the actual  
deviationsfromnormaloperatingsequence.Selecttheappli-  
cable letter(s) and proceed to the corresponding Trouble-  
shooting Procedure(s).  
IMPORTANT: At the completion of any troubleshooting  
procedure, be sure to perform the Checkout Tests  
listed in the Checkout section.  
A. Relay 3K does not pull in on a call for heat.  
B. Relay 3K pulls in but the burner motor does not start.  
C. Burner motor starts but prepurge does not stop at end  
of purge timing (relay 1K does not pull in).  
D. Relay 1K pulls in but the pilot does not light, ignition  
does not occur, or expanding pilot valve does not  
open.  
PRELIMINARY INSPECTION  
1. Disconnect power to the R4795 by opening the sys-  
tem disconnect switch.  
2. Remove the R4795 cover. Make sure all mounting  
screws are tight, and that the plug-in amplifier and purge  
timer are properly seated; refer to Fig. 10.  
E. Pilot lights but relay 2K does not pull in (control locks  
out without lighting the main burner).  
11  
60-2285—7  
 
R4795A  
TROUBLESHOOTING  
F. Pilot lights and relay 2K pulls in but the main burner  
3. Check the position of the flame relay. If relay 2K is  
pulled in, check for flame simulating condition.  
4. If the flame relay is not pulled in, clean the 2K relay  
contacts.  
does not light.  
G. Relay 2K remains in after flame is extinguished.  
H. Miscellaneous problems:  
1. Repeated lockouts or control failures.  
2. Ignition interference (flame rod installations only).  
5. Replace the purge timer with one of the same timing.  
If problem still continues, replace the R4795.  
TROUBLESHOOTING PROCEDURES  
D. Relay 1K pulls in but the pilot does not light, ignition  
does not occur, or expanding pilot valve does not open  
1. Make sure that all manual fuel valves are open.  
2. Check voltage between terminals 3 and 2, or 4 and 2,  
asapplicable. (Terminal3isusedforpilotorfirststage  
oilvalve;terminal4forignition.)Checkmustbemade  
before control locks out on safety.  
CAUTION  
1. Use extreme care while troubleshooting the  
R4795; line voltage is present on most contacts  
when power is On.  
2. Open the master switch before removing the  
cover, cleaning contacts, removing R4795 from  
subbase, or reinstalling R4795 on subbase. See  
Fig. 9 for relay location.  
3. If zero voltage, clean the 1K and 2K relay contacts;  
then recycle the system and recheck the voltage at ter-  
minal3or4. Ifterminalscannotbepowered, replacethe  
R4795.  
4. If correct voltage at terminals 3 and 4, check the pilot  
valve and ignition and the circuits.  
IMPORTANT:  
1. Clean contacts only when instructed to do so in a  
troubleshooting procedure. Follow the instructions in  
Contact Cleaning section.  
2. If, after completing an applicable Troubleshooting  
Procedure, proper operation still cannot be obtained,  
replace the R4795 (except amplifier and purge timer,  
unless noted).  
E. Pilot lights but relay 2K does not pull in (control locks  
out without lighting the main burner)  
1. Use a 121708 Rectification or a 203659 or 123514B  
Ultraviolet Flame Simulator to check the flame relay.  
Follow the instructions for the simulator.  
2. If no flame simulator is available, do a flame current  
check. If the flame current is satisfactory, replace the  
R4795. If the flame current is not satisfactory, recheck  
all items.  
A. Relay 3K does not pull in on a call for heat  
1. Check for power at terminals 1 and 2 with the control-  
ler calling for heat.  
F. Pilot lights and relay 2K pulls in but the main burner  
does not light  
a. Voltage must be within plus 10 to minus 15 percent  
of the rated voltage for dependable operation.  
b. If voltage is zero, check the continuity of the limit  
and controller contacts and check the power sup-  
ply. Look for blown fuses, open switches, and bad  
wiring connections.  
1. Check that the manual main fuel valves are all open.  
2. Check the voltage at terminal 5 when the 2K relay  
pulls in.  
a. If normal voltage at terminal 5, check the main  
valve and the external valve circuit.  
b. If zero voltage at terminal 5, clean the 2K relay  
contacts. If terminal 4 cannot be powered, replace  
the R4795.  
2. If voltage at terminals 1 and 2 is satisfactory and relay  
3K will not pull in, clean the 1K and 3K relay contacts.  
Press safety switch button several times to clean the  
contacts. If trouble persists, replace the R4795.  
G. Relay 2K remains in after flame is extinguished  
1. If the flame detector is a rectifying flame rod, install a  
new plug-in amplifier.  
B. Relay 3K pulls in but the burner motor does not start  
1. Check for power at terminal 8 when the 3K relay  
pulls in.  
2. If the flame detector is a rectifying photocell or C7012  
Ultraviolet Detector, plug the back end of the flame  
simulator into the jack of the plug-in amplifier.  
a. If that does not cause relay 2K to drop out, install a  
new plug-in amplifier.  
a. If terminal 8 is not powered, clean the 3K relay  
contacts and recheck for power. If terminal 8 can-  
not be powered, replace the R4795.  
b. If terminal 8 is powered, check the fan or burner  
motor.  
b. If plugging into the meter jack causes relay 2K to  
drop out, the trouble is caused by hot refractory  
hold-in, detector failure, or other flame simulating  
conditions.  
C. Burnermotorstartsbutprepurgedoesnotstopatend  
of purge timing (relay 1K does not pull in)  
1. Check the seating of the plug-in purge timer.  
2. Check that the airflow switch contacts are making.  
Approximately 20 Vdc should appear between termi-  
nals 7 (plus) and G (minus) when airflow switch con-  
tacts are made.  
(1) Resight the photocell at a cooler or more re-  
mote area of the refractory.  
(2) Recheck the flame detector current for the  
condition recommended in the Checkout sec-  
tion. Replace the detector if necessary.  
60-2285—7  
12  
 
R4795A  
TROUBLESHOOTING • SERVICE  
(3) Remove any flame simulating condition such  
as false light.  
(4) Note that any change made in the detector or its  
sighting requires a pilot turndown test.  
How detected. The arc gap circuit in the rectifica-  
tion amplifier (Fig. 10) protects the R4795 from igni-  
tion interference; however, it also prevents operations  
when ignition interference is present above the arcing  
level of the device. If a shutdown is caused by ignition  
interference, the arc gap protector glows.  
Continuous interference below the arcing level can  
be detected by reading the flame current with the pilot  
and ignition on; then with only the pilot on. Any sub-  
stantial difference indicates the presence of ignition  
interference.  
3. If using an R7290 Ultraviolet Amplifier, replace the  
amplifier and recheck the flame relay dropout time. If  
the flame relay dropout timing is still excessive, re-  
place the detector and check its wiring.  
4. If trouble persists, replace the R4795.  
H. Miscellaneous problems  
1. Repeated lockouts or control failures: The most com-  
mon causes of repeated failures of the control or flame  
detector, or repeated lockouts are:  
Intermittent ignition interference may be due to  
very turbulent air in the ignition electrode area. For  
arc-over elsewhere, examine the electrodes for spac-  
ing and for unusual dirt conditions or dust accumula-  
tions between the ignition leads and flame leads.  
How eliminated (tabulated in order of importance).  
1. Provide adequate flame grounding area.  
2. Be sure the ignition electrode and the flame rod  
are on opposite sides of the grounding area.  
3. Check for the correct spacings on the ignition  
electrode. Spacing should be 1/16 in. (1.6 mm)  
to 3/32 in. (2.4 mm) for 6,000V systems; 1/8 in.  
(3.2 mm) to 3/16 in. (4.8 mm) for 10,000V  
systems.  
a. High ambient temperatures over 125°F (52°C).  
Subtract 10°F (6°C) for alarm contacts and 10°F  
(6°C) for 50 Hz operation. -40°F (-40°C) models  
have a maximum ambient of +115°F (46°C) at  
60 Hz, +105°F (40°C) at 50 Hz.  
b. Supply voltage variation greater than plus 10 to  
minus 15 percent.  
c. Marginal flame signal.  
d. Faulty flame detector.  
2. Ignition interference (flame rod installations only)  
What it is. Ignition interference is a false signal  
from a spark ignition source superimposed on the  
basic flame signal. It is normally associated with a  
marginal flame reading, and usually caused by a mar-  
ginal flame ground.  
4. Eliminate any marginal spacings at other areas  
along the lead routes. Replace any deteriorated  
leads.  
Service  
operating conditions (dirt and heat especially), and the cost of  
a nuisance shutdown. Include the following in any program:  
Annually replace the vacuum tubes in the C7012 Flame  
Detector (if used).  
GENERAL  
1. Only qualified personnel should attempt to service  
heating equipment or controls.  
2. Perform all checks required in the Checkout section  
when replacing the R4795, or when relighting or restoring  
power to the system after shutdown.  
3. Captive mounting screws carry current; always dis-  
connect power before loosening or tightening the mounting  
screws.  
Perform a flame failure check and pilot turndown test  
whenever the burner is serviced, and at least annually.  
Inspect and clean the detector and any viewing windows  
as often as required by soot accumulation and heat  
conditions at the detector.  
4. On each service call, check the controller for the ap-  
proximately correct calibration and differential; assure it is  
mounted securely (see Controller installation instructions).  
5. Never use oil on any part of the R4795.  
Doaflamecurrentcheckatleastmonthly, andmoreoften  
where a shutdown may be costly.  
Clean contacts only when required by failure to operate  
properly.  
6. When cleaning the burner, clean the flame detector.  
7. DO NOT MANUALLY PUSH IN THE R4795  
RELAYS. This may damage the relays and it is an unsafe  
practice because it overrides the protective features of the  
relays. Clean relay contacts only as instructed following.  
CONTACT CLEANING  
CAUTION  
Open the master switch before removing cover or  
cleaning contacts. Line voltage is present on most  
contacts when power is on.  
PERIODIC MAINTENANCE  
The specific maintenance schedule setup will depend on  
several factors including type of equipment being controlled,  
13  
60-2285—7  
 
R4795A  
SERVICE  
IMPORTANT:  
2. Some leave an oily residue that will collect dust and  
dirt. The residue will also break down to form various  
carbonaceous products. Either result will cause early contact  
failure.  
Do not use an abrasive (sand paper stock, file, etc.) or a  
burnishing tool to clean contacts. Its use can cause early  
contact failure for these reasons:  
1. Do not clean contacts unless absolutely necessary.  
2. UseonlyHoneywellContactCleanerpartno.132569.  
Do not use any other type of contact cleaner.  
3. Use extreme care to avoid bending the contacts or  
changing the specifications or configuration in any  
way.  
4. Do not use an abrasive or a burnishing tool to clean  
contacts.  
5. Donotusehardpapersuchasabusinesscardtoclean  
contacts.  
1. Some relay contacts are plated with gold for increased  
reliability. Burnishing can quickly remove the plating.  
2. The radii or points of the contacts are designed with  
specific shapes to best serve the intended functions of the  
contacts. Burnishing can rapidly alter these contact configu-  
rations.  
3. Use of an abrasive loosens fine particles of the contact  
material that adhere to the surface of the contract, thus in-  
creasing its resistance.  
4. Contact specifications (contact pressures, press-back,  
and gaps) are carefully controlled during manufacturing to  
assure maximum contact life. Burnishing can easily change  
these specifications.  
If relay contacts must be cleaned, use only Honeywell  
Pressurized Contact Cleaner, part no. 132569. Honeywell’s  
chemical analysis laboratory has found this cleaner to be  
acceptable for this task. Directions for using this cleaner are  
printed on the can.  
Do not risk using any other types of contact cleaners.  
Honeywell’s chemical analysis laboratory tested other pres-  
surized type contact cleaners but did not approve them for  
these reasons:  
1. Some had solvents that could deteriorate plastic parts  
and wire insulation.  
60-2285—7  
14  
 
15  
60-2285—7  
 
Home and Building Control  
Honeywell Inc.  
1985 Douglas Drive North  
Golden Valley, MN 55422  
Home and Building Control  
Honeywell Limited—Honeywell Limitée  
740 Ellesmere Road  
Scarborough, Ontario  
M1P 2V9  
Printed in United States  
 

Graco Automobile Parts 3A1323C User Manual
Grizzly Automobile Parts G2527 User Manual
Gyration Mouse Full Size Keyboard User Manual
Haier TV Antenna LE58F3281 User Manual
Hasbro Robotics 85412 User Manual
Honeywell Car Video System HMLCD15 User Manual
Honeywell Modem NPB MDM User Manual
HP Hewlett Packard Laptop Docking Station 367055 002 User Manual
Hyundai Car Stereo System H CDM8019 User Manual
iHome Speaker IHM11 User Manual