Graco VRM 24F872 Instructions Manual page 21

Power Line Voltage Surges
Power conversion equipment can be sensitive to voltage
fluctuations on incoming power. The Motor Control Mod-
ule falls under the category of power conversion equip-
ment because energy is stored on a capacitive bus and
then modulated to control a brushless motor. Engi-
neered design takes this into account and withstands a
wide range of conditions, but it is possible for supplied
power to occasionally fall outside the tolerable range in
industrial plants with high-amperage reactive pulsed
loads such as welding equipment. If the tolerable range
is exceeded, an overvoltage condition is flagged and the
system will shut down in an alarm state to protect itself
and alert the user of unstable power. Excessive or
repeated overvoltage may permanently damage hard-
ware.
The MAX-HOLD feature on a multimeter can be used to
determine peak DC voltage on the line. DC is the proper
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 equip-
ment. Reading should not regularly exceed approxi-
mately 400VDC to avoid tripping the 420VDC alarm
level in the Motor Control Module. If power quality is
suspect, power conditioning or isolation of the device(s)
causing poor power quality is recommended. Consult a
qualified electrician if there are any concerns about the
available power supply.
Power Line Test Steps with Multimeter
i. Set multimeter to "DC voltage".
ii. Connect multimeter probes to supplied power line.
iii. Press "Min Max" successively to show the peak
positive and negative DC voltages.
iv. Confirm readings do not exceed 400VDC (Motor
Control Module alarm issued at 420VDC).
313873J
The chart below shows the permissible magnitude and
duration of temporary over-voltage events:
Maximum Permissible Transient Voltage Surges
* Constructed from ITIC 1996 curve, referenced by IEC 61000-2-4
1400
<--1 MW Max Surge Power
1200
1200Vac, 1697Vdc
1000
800
600
480Vac, 679Vdc
400
336Vac, 475Vdc
200
0
0.000001 0.00001 0.0001
Ground the system.
3.
This equipment must be grounded.
a. VRM: grounded through power cord. See Con-
nect Electrical Cord, step #2 on page 20.
b. Dispense Valve: follow your local code.
c. Fluid supply containers: follow your local code.
d. Dispensing target/container: follow your local
code.
e. Solvent pails used when flushing: follow your
local code. Use only metal pails, which are con-
ductive, placed on a grounded surface. Do not
place pail on a nonconductive surface, such as
paper or cardboard, which interrupts grounding
continuity.
f. To maintain grounding continuity when flushing
or relieving pressure, hold grounded metal pail
firmly to a metal part of dispense valve then initi-
ate a dispense.
<--150 KW Max Surge Power
<--50 KW Max Surge Power
<--No Power Limit
288Vac, 407Vdc
264Vac, 373Vdc
0.001 0.01 0.1 1
Time (seconds)
Setup
10
21