Honeywell Replacing RA890E,F,G with R4795A, R4795C Replacement, Flame Detector Wiring

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R4795A

INSTALLATION

Replacing RA890E,F,G with R4795A

1.Disconnect all wires from terminal 1, and splice with solderless connector. (If RA890 has no terminal 1 wiring, disregard this step.)

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.

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.

6.Check for proper operation through at least two cycles.

Fig. 4—Replacing RA890E,F,G with R4795A on gas or oil burner.

REPLACING RA890 WITH R4795 ON GAS OR OIL BURNER

R4795C Replacement

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.

Flame Detector Wiring

See Fig. 6.

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.

If a line voltage alarm is used with the R4795, mount the entire control in a suitable enclosure.

 

 

 

 

 

 

 

 

Fig. 5—When R4795A replaces R4795C in a

BEFORE

standing pilot application, install relay 1R to

CONTROLLER HIGH LIMIT

 

prevent detection of pilot flame during burner

MAIN GAS

 

 

 

 

 

 

 

off cycle.

 

 

 

 

 

 

 

VALVE OR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2ND STAGE

 

 

 

 

 

 

 

 

OIL VALVE

 

 

 

6

 

5

 

 

 

 

 

 

 

 

 

 

 

IGNITION

 

 

 

 

 

 

 

 

 

T

 

TRANSFORMER

 

 

 

 

 

MIAN FUEL

 

 

 

 

4

 

BURNER

 

5

 

 

 

 

 

 

 

8

VALVES

 

 

 

 

 

BURNER

 

MOTOR

2K3

 

 

 

 

 

 

 

 

 

 

 

T

 

MOTOR

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

FLAME

 

 

 

PILOT OR

 

 

 

7

2K2

 

 

 

F

 

OIL VALVE

 

 

 

 

 

 

 

DETECTOR

 

 

 

L1

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

 

1

(HOT)

 

 

 

1R

 

 

 

 

 

AIR FLOW

 

 

 

 

 

 

 

 

 

 

1K4

 

 

 

G

 

 

120V

6

 

 

 

 

 

 

SWITCH

 

 

 

 

 

2

L2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RA890 WITH Q270

 

 

 

1R1

 

3K2

 

 

 

 

 

 

 

F

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TO FLAME

 

FLAME

 

 

AFTER

 

 

 

 

 

DETECTOR

 

AMPLIFIER

 

 

 

 

 

 

 

 

 

G

 

 

 

 

CONTROLLER

HIGH LIMIT

 

 

 

 

 

 

 

 

(FLAME ROD

 

 

 

 

 

 

 

 

MAIN GAS

 

 

1

CONTROLLER

 

 

 

 

 

 

OR UV

 

 

 

 

 

 

VALVE OR

 

 

 

 

 

 

 

 

 

2ND STAGE

 

DETECTOR)

 

 

 

 

 

 

 

 

OIL VALVE

 

 

 

 

3

 

 

 

6

8

 

5

 

 

 

 

2

 

 

 

 

 

 

 

 

 

LIMIT(S)

2

 

 

 

 

IGNITION

 

 

 

 

 

 

 

AIR FLOW

 

 

 

TRANSFORMER

 

 

 

R4795A

 

 

T

7

 

4

 

 

 

 

 

SWITCH

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BURNER

 

 

 

 

 

 

 

 

T

6

 

MOTOR

 

 

 

 

 

 

 

 

 

3

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

SODERLESS

PILOT OR

 

 

 

 

L2

L1

 

 

 

 

 

 

 

(HOT)

 

FLAME

 

 

 

 

 

 

 

F

CONNECTION

OIL VALVE

 

 

 

 

 

 

 

 

 

 

 

 

 

DETECTOR

 

 

 

 

L1

1

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD

 

 

 

 

 

 

 

 

 

 

 

PROTECTION AS REQUIRED.

 

 

 

 

 

 

 

(HOT)

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

G

 

 

120V

2

REFER TO SPECIFICATIONS SECTION FOR RECOMMENDED LIMITS.

 

 

 

 

 

 

 

RA4795 WITH Q270

2

L2

3

LOW VOLTAGE CIRCUIT OMITTED.

 

M8685

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M8684

 

 

 

 

 

 

60-2285—7

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Contents R4795A Flame Safeguard Primary Controls Specifications Ordering InformationTerminal Load Rating ApprovalsInstallation Wiring to SubbaseLocation Wiring Hookups Retrofitting R4795Alarm Contacts R4795C ReplacementFlame Detector Wiring Replacing RA890E,F,G with R4795AMounting R4795 On Subbase C7027, C7035, or C7044 Ultraviolet Flame DetectorCheckout Checkout SummaryPreliminary Inspection Flame Current Check Pilot Turndown TestSafe Shutdown Checks Power FailureIgnition Spark Response Test UV Detectors Limit ActionOperation TroubleshootingSafety Operation Normal Operation Refer toRelay 3K pulls in but the burner motor does not start Troubleshooting ProceduresRelay 3K does not pull in on a call for heat Relay 2K remains in after flame is extinguishedPeriodic Maintenance ServiceMiscellaneous problems Contact CleaningService 60-2285-7 Home and Building Control