Troubleshooting the Graco Motor Control
Power Line Voltage Surges
Power conversion equipment can be sensitive to
voltage fluctuations from the incoming power supply.
The Graco Motor Control is considered to be power
conversion equipment because energy is stored on
a capacitive bus and then modulated to control a
brush-less motor. The design of the Graco Motor
Control takes this into account, and therefore can
withstand a wide range of conditions. However, it
is still possible for supplied power to occasionally
go outside of the tolerable range in industrial plants
with high-amperage reactive pulsed loads, such as
welding equipment.
If the tolerable range is exceeded, an over-voltage
condition is flagged and the system shuts down in
an alarm state for protection and to alert the user of
unstable power. Excessive or repeated over-voltage
events may permanently damage the hardware.
The MAX-HOLD feature on a multimeter can be used
to determine peak DCvoltage on the line. DCis the
correct setting, as opposed to AC, because peak
voltage is the critical parameter that affects the DC
voltage level stored on the capacitive bus in power
conversion equipment.
Readings should not regularly exceed approximately
400 Vdc to avoid tripping the 420 Vdc alarm level
in the Graco Motor Control. If the power quality is
suspect, it is recommended to power condition or
isolate the device(s) that is causing the poor power
quality. Consult a qualified electrician if there are any
concerns about the available power supply.
Test Power Line with Multimeter
1. Set multimeter to DCvoltage.
2. Connect the multimeter probes to the supplied
power line.
3. Press Min Max successively to show the peak
positive and the negative DCvoltages.
4. Confirm that readings do not exceed 400 Vdc
(Graco Motor Control alarm is issued at 420 Vdc).
334188P
45
Tel: 866-777-6060
Fax: 866-777-6383
Springer Pumps, LLC
Website: www.springerpumps.com
Int'l: +001 267 404 2910
