White Rodgers 37-5488A, 8B43A-601 specifications Dial Setting, Wiring and Operation

INSTALLATION CONT.

3.Insert sensing bulb into well, forming capillary so bulb bottoms in well. Raise control onto well, slipping flange on well between back of case and well clamp. Be sure well fits snugly into hole in case. Then tighten well clamp screws evenly and securely.

WELL

CLAMP

ADAPTOR	CONTROL CASE
FLANGE
	WELL ADAPTOR
	(F71-0924)

CAUTION

Do not dent or bend the bulb of the temperature sensitive element as this will prevent it from fitting

Fig. 1

MOUNTING TO EXISTING WELL (for types with well adaptor)

CAPILLARY

BULB

properly into the well.

For best control performance it is recommended that the existing well be replaced with a well shown on page 3. However, by using the heat conductive grease supplied in tube, these controls will give satisfactory performance when used with larger-diameter existing wells of many controls.

Use of adaptor requires that the existing immersion well be equipped with a set screw. After removing old control, install new one as follows:

1.Remove cover and loosen two screws holding well clamp.

2.Fit capillary into slot in adaptor and push adaptor snugly into opening in back of case so adaptor flange fits between well clamp and case. Then tighten well clamp screws evenly and securely.

3.Apply heat conductive grease (supplied in tube) to fill void between bulb and well.

4.Insert bulb into existing well, forming capillary so bulb contacts bottom and side of well. Attach control to well by tightening set screw securely. (Be sure set screw is not directly above slot in well adaptor before tightening.)

DIAL SETTING

When replacing an existing control, adjust settings to
correspond with those of the old control.	HIGH LIMIT	LO LIMIT - CIR.
Setting the High Limit
	160 140	200 180
	180	160

Set pointer to temperature at which contacts are to open.

Setting the Low Limit-Circulator

1. Set brass pointer to lowest temperature of cycle.

2. Set aluminum pointer to highest temperature of cycle.	POINTER
NOTE	200	220	240	100	120 140
	SET HIGH LIMIT 20° OR MORE
Always set the high limit 20° or more above the low
		ABOVE LOW LIMIT
limit.			Fig. 2

ALUMINUM POINTER

BRASS POINTER

WIRING AND OPERATION

All wiring should be done in accordance with local and national electrical codes and ordinances.

The diagram below shows wiring connections for a typical oil-fired installation. Operation is as follows:

When the room thermostat is not calling for heat, the low limit-circulator control operates the burner motor as necessary to maintain the domestic hot water supply at the desired temperature (burner “on” when R-B contacts are closed).

If boiler temperature exceeds the setting of the high limit, the burner motor stops. If thermostat is calling for heat, the circulator continues to run.

EXTERNAL WIRING		INTERNAL WIRING		LOW VOLTAGE
			Line Voltage
	Line Voltage			THERMOSTAT
	Low Voltage		Low Voltage

When the room thermostat closes its contacts, the relay HOT

TRANSFORMER

1

coil is energized and closes its two sets of relay contacts. LINE

LOW LIMIT-CIRC.

#1 RELAY

T1 T2

The burner starts as the No. 1 Relay Contacts close. If the N R-W contacts of the low limit-circulator control are closed, the circulator motor also starts as the No. 2 Relay Contacts close. If the R-W contacts open while the thermostat is calling for heat, the circulator motor stops but the burner stays on.

When the room thermostat is satisfied, the circulator motor stops as the No. 2 Relay Contacts open. The burner motor also stops as the No. 1 Relay Contacts open, unless the R-B contacts of the low limit-circulator

2

CONTROL

B
R	ZC
W	ZC

#2 RELAY

CONTACT

C1

C2

CONTACT

S1	HIGH
	LIMIT
S2

B1

B2

RELAY

COIL

Z

TYPE 668 OIL

BURNER CONTROL

(LINE VOLTAGE)

IGNITION

TRANS.

BURNER

MOTOR

are closed.

CIRCULATOR

MOTOR

Fig. 3

2