Honeywell R4795A specifications Checkout Summary, Preliminary Inspection

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R4795A

CHECKOUT

Checkout

CAUTION

Use extreme care while testing the R4795; line voltage can be present on most terminals when the power is On.

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.

Preliminary Inspection: All installations.

Flame Current Check: All installations.

Fig. 10—Internal view showing amplifier and test jack for flame current test.

ARC-GAP IGNITION INTERFERENCE

PROTECTION (R7289 RECTIFICATION

AMPLIFIER ONLY)

ST71A

TEST JACK

PLUG-IN

 

PURGE

 

TIMER

 

 

PLUG-IN

 

AMPLIFIER

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.

PURGE TIMER CONNECTORS

AMPLIFIER CONNECTORS

Ignition Spark Response Test: All ultraviolet detector applications.

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.

Fig. 9—Internal components of R4795A.

3K

2K

 

CAPTIVE

1K

MOUNTING

UNDER

SCREWS

COVER

(10)

OPTIONAL

ALARM TERMINALS

M8680

PRELIMINARY INSPECTION

Make certain that:

1.

Wiring connections are correct and all terminal screws

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.

Correct combination of amplifier and flame detector is

used. Refer to Plug-In Flame Signal Amplifiers in Specifica-

tions section.

PLUG-IN PURGE TIMER (ST71A)

SAFETY SWITCH RESET BUTTON

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).

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

TRANSFORMER

PLUG IN AMPLIFIER (R7289–GREEN–RECTIFICATION)

(R7290–PURPLE–ULTRAVIOLET)M8679

IMPORTANT: Anytime you reset the safety switch, wait at least one minute after it trips to allow the heater to cool before pushing in the reset button.

CAUTION

Make initial pilot lightoff with manual main fuel shutoff cock closed.

60-2285—7

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Contents R4795A Flame Safeguard Primary Controls Specifications Ordering InformationTerminal Load Rating ApprovalsLocation InstallationWiring to Subbase Wiring Hookups Retrofitting R4795R4795C Replacement Flame Detector WiringAlarm Contacts Replacing RA890E,F,G with R4795AMounting R4795 On Subbase C7027, C7035, or C7044 Ultraviolet Flame DetectorPreliminary Inspection CheckoutCheckout Summary Flame Current Check Pilot Turndown TestPower Failure Ignition Spark Response Test UV DetectorsSafe Shutdown Checks Limit ActionTroubleshooting Safety OperationOperation Normal Operation Refer toTroubleshooting Procedures Relay 3K does not pull in on a call for heatRelay 3K pulls in but the burner motor does not start Relay 2K remains in after flame is extinguishedService Miscellaneous problemsPeriodic Maintenance Contact CleaningService 60-2285-7 Home and Building Control