N1500i FACS Manual
75
Part No. 729-110-053 V.1.03
© 2018 Nelson Stud Welding, Inc. All rights reserved.
Likely problems or items to check - in order from most likely to least
likely:
1. Measure the primary voltage and make sure it is within
the correct range as defined by the voltage setting on the
back of the unit.
2. Improper adjustment of voltage-to-frequency circuit to
switch board. Each switch board has a pair of wires to
provide an open- collector signal to the FACS input board.
These pairs carry a pulsed 15V signal with a frequency in
the 3000Hz range that represents the primary voltage.
The signal is controlled by the switch board. If this
frequency is below 1000Hz, it will be read by the control
as zero (0Hz). Once this error occurs, the control may not
update the frequency on the display. The reading must be
in the normal range for this adjustment to be made. As
you turn the potentiometer on the switch board to adjust
the V-F measurement, observe F18 on the user interface
on both left and right sides to tune it in to the measured
voltage on J1 of the switch board. Press the time up/ down
arrows to switch from left/right measurements and to dis-
play. If this error occurs and you suspect an adjustment is
needed, turn the potentiometer to half way of the full scale
and tune from there. You'll have to get past this error to
tune the voltage readings correctly, which will involve
some power down/up cycles.
3. Broken connection from FACS input board to the switch
board in V-F circuit. Check control board JP1 pins 1, 9 for
one pair, 2, 10 for the other.
4. If the input voltage measures to be correct and the switch
boards V-F signal cannot be calibrated replace the switch
board.
5. If the V-F signal is in a range of (2314Hz and 4529Hz or
250V - 470V) and when first powered up, you still get this
error, replace the FACS input board.
