High Country Tek HAU Series - Manual (Page 6)

HAU Product Manual
High Country Tek, Inc.
208 Gold Flat Court
Nevada City, CA, 95959.
Tel:- (1) 530 265 3236
www.hctcontrols.com 021-00140_HAU_User_Guide_Rev_Bp2 6/10
If the +COIL to -COIL terminals are shorted, the valve driver will shut down its output until the short is
removed.
Disconnect the wires going to the +COIL and -COIL terminals and measure the resistance between the
wires to ensure the coil is in good condition and within resistance range given by the manufacturer
Check the card at full on & full off:
NOTE: Do not try the full on test if the power supply is 50% higher than the coil's rated voltage.
Temporarily disconnect all wires from the ‘VOLT’ and ‘CUR’ inputs.
To test the card at full on, turn the MAX and MIN potentiometers 10 turns CW and temporarily connect
the ‘VOLT’ and ‘REF’ terminals.
Measure the voltage from ‘+COIL’ to ‘-COIL’ and from ‘+POWER’ to ‘PWR COM’.
The voltage difference should be no more than one volt if the card is operating correctly.
To check the card at full off, disconnect the ‘VOLT’ and ‘REF’ terminals and turn the MAX potentiometer
10 turns CW and the MIN potentiometer 10 turns CCW.
The +COIL to -COIL voltage should be zero.
If the valve won't fully shift:
If the card passes the "full on test" above, the problem maybe in the electrical system.
Command the valve to full output.
Measure the modules supply voltage at the main DCV power supply or battery source and then measure
the voltage across the controllers +PWR and GND terminals.
Compare these readings, they should be within 0.5V of each other, If there is excessive voltage drop in
any of those wires i.e. >1V, they should be shortened or replaced by bigger wires.
Bad frame 0V (GND) connections can cause large voltage drops and operational interruption.