Honeywell R4795A specifications Wiring Hookups, Retrofitting R4795

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IMPORTANT: Do not run high voltage ignition trans- former wires in the same conduit with the flame detector wiring.

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.

Wiring Hookups

The typical wiring hookups in Fig. 2 and 3 show the internal line voltage schematic. Contact 3K2 closes when the 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.

Fig. 2—Wiring hookup of gas system with interrupted ignition and intermittent pilot.

BURNER

 

5

MAIN FUEL

 

8

VALVE(S)

 

MOTOR

2K3

 

 

 

 

 

AIR FLOW

 

4

IGNITION

2

7

 

SWITCH

2K2

 

 

 

 

 

 

 

 

 

 

6

3

PILOT

 

 

VALVE

 

 

 

1K4

 

 

 

 

 

 

 

3K2

 

 

TO FLAME

F

 

 

 

DETECTOR

 

FLAME

 

 

(FLAME ROD

 

 

 

 

AMPLIFIER

 

 

OR UV

 

 

 

G

 

 

 

DETECTOR)

1

CONTROLLER

 

 

 

2

 

3

 

 

 

LIMIT(S)

 

 

R4795A

 

 

 

 

 

1

 

 

 

L2

L1

 

 

 

(HOT)

 

 

 

 

 

1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

2FOR INTERMITTENT IGNITION, CONNECT IGNITION TO TERMINAL 3.

3REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.

M8682

R4795A

INSTALLATION

Fig. 3—Wiring hookup of oil system with interrupted ignition.

BURNER

 

5

2ND STAGE

4

8

OIL VALVE(S)

 

MOTOR

2K3

 

 

 

 

 

AIR FLOW

 

4

IGNITION

2

7

 

SWITCH

2K2

 

 

 

 

 

 

 

 

 

 

6

3

1ST STAGE

3

 

 

 

OIL VALVE(S)

 

 

 

1K4

 

 

 

 

 

 

 

3K2

 

 

 

F

 

 

 

TO FLAME

 

FLAME

 

 

DETECTOR

 

 

 

 

AMPLIFIER

 

 

(PHOTOCELL

 

 

 

G

 

 

 

OR UV)

1

CONTROLLER

 

 

 

2

 

5

 

 

 

LIMIT(S)

 

 

 

 

 

 

R4795A

 

 

 

 

 

1

 

 

 

L2

L1

 

 

 

(HOT)

 

 

 

 

 

1POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.

2FOR INTERMITTENT IGNITION,CONNECT IGNITION TO TERMINAL 3.

3IMMEDIATE OPENING OIL VALVE V4046B.

4OPTIONAL DELAYED OPENING OIL VALVE V4046A OR V4046B WITH ST70A ELECTRONIC TIME DELAY.

5REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.

M8683

Retrofitting R4795

CAUTION

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.

Observe the following when retrofitting the R4795:

1.Requires a line voltage controller capable of switching 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.

3.Refer to Fig. 2, 3 or 4 for proper wiring connections.

5

60-2285—7

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Contents R4795A Flame Safeguard Primary Controls Ordering Information SpecificationsApprovals Terminal Load RatingLocation InstallationWiring to Subbase Retrofitting R4795 Wiring HookupsFlame Detector Wiring R4795C ReplacementAlarm Contacts Replacing RA890E,F,G with R4795AC7027, C7035, or C7044 Ultraviolet Flame Detector Mounting R4795 On SubbasePreliminary Inspection CheckoutCheckout Summary Pilot Turndown Test Flame Current CheckIgnition Spark Response Test UV Detectors Power FailureSafe Shutdown Checks Limit ActionSafety Operation TroubleshootingOperation Normal Operation Refer toRelay 3K does not pull in on a call for heat Troubleshooting ProceduresRelay 3K pulls in but the burner motor does not start Relay 2K remains in after flame is extinguishedMiscellaneous problems ServicePeriodic Maintenance Contact CleaningService 60-2285-7 Home and Building Control