31
4.0
Trouble-shooting Check List
Preliminary:
Use manual drain option to check pump operation
Symptom
Check/Cause/Remedy
Power-On Neon – Off
Symbol-LED – Off
Display - Blank
Check main power is connected and switched on.
Check power supply fuses.
Power-On Neon – On
Symbol-LED – On
Display - Blank
Check if security circuit is open circuit
Check 24V 3.15A fuse mounted at top of Microvap
controller PCB 1150630
Automatic STOP –
Feed Fault indicated on the Display.
Possibilities
Checks
Water is not connected
Check water stop valve is open
Water connected but not reaching cylinder.
Check internal Vapac hose connections for a leak.
Water in cylinder and overflowing
.
Check float switch operation
Automatic Stop –
Drain Fault indicated on the display.
Possibilities
Checks
Drain pump function impaired
If pump will not function, empty cylinder by disconnecting
at the tundish fill-cup the water supply hose to the
cylinder and draining the water into a bucket. Remove,
dismantle and clean pump.
Float switch failure
Check float switch operation
Cylinder O/Let Blocked
Check & unblock
Unit On-Line but inadequate or no steam production
.
Possibilities
Checks
Contactor not made
Contactor coil, Float switches, Control PCB.
MCB’s tripped
Cylinder Inspection, inspect elements and float switch
operation.
SSR’s not switching
SSR Check as described below,
Specialized check of the Solid State Relay
Important: The following check should be carried out by a competent electrician
Equipment needed:
An AC Voltmeter, multi-meter set to full AC line voltage or suitable voltage test instrument.
Procedure:
1)
Remove access panels from both the steam cylinder and electrical compartments
2)
Ensure that the humidifier has an operational level of water in the cylinder. Switch unit
on and check that the display indicates “Vapac on line”.
3)
Apply the voltmeter, set to the full line Voltage, across the output terminals of the SSR
being tested (i.e. the two terminals carrying the cabling to the elements).
Correct Voltmeter Response – oscillating between full and near zero Voltage.
If Voltmeter reads a constant near zero Volts, Check:
a)
That the unit is not feeding water – if it is, wait until the feed valve closes and then re-
check. The reason for this is that the SSR will hold closed while the feed valve is open).
b)
That the control PCB is giving the correct pulsed D.C. signal (approx 5V D.C.) to the
SSR control input terminals.
SSR Replacement:
A faulty SSR should be replaced with an SSR of the same (or higher) Voltage and
amperage rating. Disconnect the unit from the electrical supply. Disconnect the SSR and
undo the mounting screws. The SSR is bedded in thermal compound to assist heat
transfer – it is important that this is cleaned off, and a layer of fresh compound placed
under the replacement SSR, when it is secured in position.
Reconnect the SSR, reconnect the electrical supply and check the SSR function (as
above) before replacing the access panels.
Note: Use proprietary thread locking compound on the line voltage terminals of the
SSR’s.
