Vulcan-Hart MHB24G, VHX24G5 manual Water Level Controls, Test

VHX SERIES STEAMER - SERVICE PROCEDURES AND ADJUSTMENTS

used, a frequent interval should be used. This			should be inspected.
blowdown procedure is essential to proper operation			WARNING: THE FOLLOWING STEPS REQUIRE
and component life by removing sediment and
			POWER TO BE APPLIED TO THE UNIT DURING
scalants that may be lodged in the probe housing.
			THE TEST. USE EXTREME CAUTION AT ALL
NOTE: Boiler should be within normal operating
			TIMES.
pressures.			Main Water Level Control
1.	Remove the left side boiler base panel to
			NOTE: The main water level control is a dual
	access the ball valve.
			functioning control that provides for low level cut-off
2. Turn the power switch ON and allow the boiler
			protection and differential water level control
	to reach operating pressure.		1. Turn power switch ON and verify:
WARNING: THE STEAMER AND ITS PARTS ARE
				A.	Low water light is illuminated (front control
HOT. USE CARE WHEN OPERATING, CLEANING
					panel).
OR SERVICING THE STEAMER. THE BOILER
CONTAINS LIVE STEAM. STAY CLEAR WHEN				B.	HL LED is illuminated on the water level
OPENING THE VALVE.					control board.
3. Open the ball valve for approximately one				C.	Boiler is filling with water.
	minute while under pressure to thoroughly flush				1) If boiler isn’t filling with water:
	the probes and housing.
4.	Close the ball valve and replace left side panel.				a.	Verify 120 Volt AC is being
						applied to the fill valve.
5.	Press the reset switch (manual) on the boiler
					b.	Verify fill valve isn’t clogged.
	control panel and allow boiler to reach
	operating pressure.				c. Verify 120 Volt AC is on main
6.	Steamer is now ready for use.					water level control board.
					2) If water level control board doesn’t
	WATER LEVEL CONTROLS
					have 120 Volt AC:
	TEST				a. Check it’s power source at the
						10 pin J3 connector, pin 1
The procedure below applies to the water level						(white) and pin 2 (black).
						Disconnect the 10-pin J3
control boards for both the old and new style boiler
						connector from the relay board
controls. For additional information related to the
						in the main boiler control box.
new style controls, refer to "RELAY BOARD" and
					b. If no voltage is measured on J3
"SEQUENCE OF OPERATION" under
"ELECTRICAL OPERATION". For specific						pins 1and 2, check the F1 fuse
information related to the water level controls						(resettable circuit breaker) in the
operation, refer to "WATER LEVEL CONTROLS"						main control box, and the power
under "ELECTRICAL OPERATION".						switch connections in the power
Loose electrical connections may prevent the						switch box.
					c. If 120 volt AC was measured on
steamer from operating properly.
An accumulation of lime scale on or near the water						J3 connector pins 1 and 2 but
						not on the water level control
level sensing probes may cause them to retain
						board, verify wire connections.
water (moist) on the probe surface and give a false
						There should be continuity
reading. Also, a cracked or damaged insulator may
						between L1 on the water level
give a false reading.
						control board and J3 pin 7.
These conditions may cause one or more of the						There should also be continuity
following to occur:						between L2 on the water level
• Gas burner no ignition						control board and J3 pin 6. This
						path includes connections thru
•	Boiler no fill					the J1 connector.
•	Boiler overfill.		2. At the end of the initial fill:
• Boiler no fill and dry fire				A.	Verify approximately one inch of water
NOTE: Dry firing may cause damage to the heat					visible in the boiler sight glass.
				B.	Verify "green" ready light in the reset
exchanger, burner assembly or the boiler. If this
condition is suspect, the affected components					switch is illuminated.
		Page 25 of	68				F24700 (October 2001)