Bunn TU3 service manual SERVICE cont, Sweetener Solenoid Valve Optional

SERVICE (cont.)		5.	Check the solenoid valve for coil action. Connect
SWEETENER SOLENOID VALVE (OPTIONAL)
			the brewer to the power source, place the ON/OFF
			switch in the ÒONÓ position and momentarily place
			the start switch in the lower position and release.
			Listen carefully after the approximate setting on
			the delay dial in the vicinity of the solenoid valve
			for a ÒclickingÓ sound as the coil magnet attracts
			and after the approximate setting on the dilution
			dial, repels the plunger.
		6.	Disconnect the brewer from the power source.
		If the sound is heard as described and sweetener will
		not pass through the solenoid valve, there may be a
	P1277.40	blockage in the sweetener line before or after the so-
	FIG. 20 SWEETENER SOLENOID VALVE	lenoid valve or, the solenoid valve may require inspec-
		tion for wear, and removal of particles.
Location:		If the sound is not heard as described, replace the
	Viewing the brewer from the rear the sweetener	solenoid valve.
solenoid is mounted on the right side of the solenoid
mounting bracket which is secured to the trunk base.		Removal and Replacement:
		1.	Remove all wires from the solenoid valves.
Test Procedure:		2.	Turn off the sweetener supply to the brewer.
1. Disconnect the brewer from the power source.		3.	Disconnect the water lines to and from the sole-
2.	With a voltmeter, check the voltage across the		noid valves.
	brown/white and white/violet wires on the sweet-	4.	Remove the two #8-32 keps nuts holding the
	ener solenoid terminals when the ON/OFF switch		mounting bracket to the trunk base.
	is in the ÒONÓ position and the start switch is mo-	5.	Lift out the bracket.
	mentarily placed in the lower position. Connect	6.	Remove the two #10-32 slotted-head screws hold-
	the brewer to the power source. After the approxi-		ing the solenoid valve to the mounting bracket.
	mate setting on the delay dial, the indication must	7.	Securely install the new solenoid valve to the
	be:		mounting bracket.
	a) 120 volts ac for two wire 120 volt models.	8.	Attach the mounting bracket to the trunk base.
	b) 240 volts ac for two wire 240 volt models.	9.	Securely fasten the sweetener and water lines to
	c) 100 volts ac for two wire 100 volt models, re-		and from the solenoid valves.
	main for the approximate setting on the dilution	10.	Refer to Fig. 21	when reconnecting the wires.
	dial, and then return to its previous indication.
3.	Disconnect the brewer from the power supply.	WHI/VIO to Dilution WHI/GRN to
		Solenoid
			Brew Timer TL4		WHI/VIO to Brew Solenoid
If voltage is present as described, proceed to #4.
					WHI/VIO to Brew Timer TL1
If voltage is not present as described, refer to the Wir-					WHI/BLU to Dilution
ing Diagrams and check the wiring harness.
					Timer TL4
4. Remove both wires from the coil and check for		BREW			WHI/VIO to Dilution
	continuity across the coil terminals. If continuity	SOLENOID			Solenoid
	is present as described, reconnect the brown/white		DILUTION		BRN/WHI to Selector
					Switch
	and white/violet wires and proceed to #5.		SOLENOID
				SWEETENER
If continuity is not present as described, replace the
				SOLENOID (Optional)
solenoid valve.			FIG.21 SOLENOID VALVE TERMINALS			P1278
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