Burnham K50 Minimum Input Adjustments, V8944B Combination Valve, Motorized Modulating Actuator

CAUTION

The following procedures should only be performed by a qualified service technician.

15.MINIMUM INPUT ADJUSTMENTS

This section covers Minimum Input Adjustments on Honeywell V8944B Diaphragm Type “Lo-Hi-Lo” Gas

Valves, Honeywell V5055B Fluid Power Gas Valves equipped with either a V4062A “Lo-Hi-Lo” Actuator or a V9055A “Modulating” Actuator.

a.Minimum Input Adjustments – “Lo-Hi-Lo” Combination Valve, V8944B (Natural Gas Only)

On boilers equipped with the V8944B combination diaphragm valve/regulator, Low Fire Adjustment should not be less than Minimum Input shown on Rating Plate (1/3 of full rated input). Fig. 57 shows the outlet pressure adjustment screws for low and high fire. The V8944B low and high fire pressure settings are factory set at 0.8” and 3.5” W.C. respectively. If further adjustments are necessary, remove pressure regulator adjustment caps and insert a screwdriver to raise or lower the regulator pressure.

Fig. 57

V8944B COMBINATION VALVE

b. MINIMUM INPUT ADJUSTMENTS – “LO-HI-LO” MOTORIZED ACTUATOR, V4062A

(1)	With power to actuator “off”, remove the
	wiring compartment cover.
(2)	Check to be sure the low fire adjustment is set
	at MAX to insure a safe light-off. (Low fire
	adjustment is preset at factory in the MAX
	position.)
(3)	Disconnect the controller lead from terminal #4
	on the actuator to keep the valve in the low fire
	position.
(4)	Start the system and establish the main burner
	flame.
(5)	Loosen the setscrew in the cam (Fig. 58A) with
	the special wrench taped to inside of actuator
	cover. Keep the wrench seated in the setscrew.
	Rotate the cam slightly downward (by moving
	the wrench toward the base of actuator) to open
	bleed valve. Actuator will start to close.
(6)	When valve reaches desired low fire position,
	quickly tighten setscrew and remove wrench. If
	the desire low fire setting is “missed”, merely
	loosen the setscrew and rotate cam in the
	opposite direction to the desired set point.
(7)	Shut down burner, and then restart. Repeat
	several times to be sure the low fire setting
	is that desired and suitable for correct burner
	lightoff. Readjust if necessary.
(8)	Disconnect power and reconnect controller lead
	removed in step (3) above.
(9)	Replace the wiring compartment cover.
c. MINIMUM INPUT ADJUSTMENTS –
MOTORIZED “MODULATING” ACTUATOR,
V9055A
On boilers equipped with Fluid Power Valves that
have “Modulating” Actuators, Low Fire Adjustment
should not be less than Minimum Input shown on
Rating Plate (1/3 of full rated input).
Fig. 58B shows the Low Fire Adjusting Screw
for increasing or decreasing low fire input on the
Honeywell V9055A “Modulating” Actuator. To
adjust the low fire setting after the burners are “on”,
the following procedure should be used.
(1)	With power to actuator “off”, remove the wiring
	compartment cover.
(2)	Check to make sure the low fire adjustment is
	set at MAX (full clockwise) to insure a safe
	light-off. (Low fire adjustment is preset at the

72

On boilers equipped with Fluid Power Valves that have “Lo-Hi-Lo” Actuator, Low Fire Adjustment should not be less than Minimum Input shown on Rating Plate (1/3 of full rated input).

Fig. 58A shows the Limit Switch Cam and Scales to indicate direction to rotate cam for increasing or decreasing low fire input on the Honeywell V4062A “Lo-Hi-Lo” Actuator. To adjust the low fire setting after the burners are “on”, the following procedure should be used.

	factory in the MAX position.)
(3)	Remove the lead to V9055A terminal R.
	Jumper terminal R to W. This will prevent the
	actuator from going to the high fire position.
(4)	Energize the system and light the main burner.
(5)	Use a Phillips screwdriver, or standard type with
	a blade no more than 3/16 inch wide, to turn
	the low fire adjusting screw for the desired low
	fire position. DO NOT PUSH INWARD ON
	SCREW.