6 © 2010 SymCom, Inc. All Rights Reserved
PROGRAMMABLE PARAMETERS
The following settings are described as they would appear on a production unit.
All parameters are
actual values except for the VUB and CUB settings; these are programmed as percentages. The
range each parameter can be programmed is found in the electrical specifications table.
Recommended settings for the 777-P2-DEMO unit are listed below in
BOLD
text with the parameter
descriptions. Failure to program all setpoints could prevent the demo from working properly.
LV/HV-
The recommended settings for LV (low voltage) and HV (high voltage) depend on many
factors such as motor usage, motor size, environmental factors and tolerance of the motor.
The motor manufacturer should be consulted for HV and LV settings. However, the NEMA
MG1 standard recommends that LV and HV be set to no more than ±10% of the motor's
nameplate voltage. The setting can be determined by multiplying the motor's nameplate
voltage by the recommended percent over and under voltage. (e.g., the motor nameplate
voltage is 480V, set LV 0.9x480=432V, set HV to 1.10x480=528V) LV cannot be set higher
than HV, so HV may have to be adjusted higher before the proper LV setting can be
programmed.
SET LV AT "432" AND HV AT "528."
VUB
- Voltage Unbalance. The NEMA MG1 standard says a motor should not be operated above
a 1% voltage unbalance without derating
the motor. Most utility supplied power sources
have a difficult time sustaining a 1% VUB. The motor manufacturer should be consulted for
an exact VUB setting. Setting VUB to 999 will disable voltage unbalance protection, but will
not disable voltage single-phase protection. Voltage unbalance is calculated as follows:
%Voltage Unbalance = [(Maximum deviation from the average)/Average] x 100%
SET AT "5."
MULT
- MULT (multiplier) setting is determined by the number of passes of the motor leads or the
size of external CTs and the full load amps of the motor the unit will be monitoring. MULT
sets the trip point range for undercurrent, overcurrent and ground fault current faults. Set
MULT first, then set UC, OC and GF.
SET AT "1."
OC
-
Overcurrent. Is typically set to the service factor amperage (SFA) of the motor or 100-135%
of motor full-load amps (FLA), which are determined by the motor manufacturer. The value
must be higher than UC. If any one leg exceeds the OC setting, the 777-P2-DEMO will trip
according to the Trip Class (TC) settings.
SET AT "60".
UC
-
Undercurrent. Is most commonly set to 80% of the full-load amperage (FLA) of the motor.
This is usually adequate for protection of loss of load for many pumps and motors, including
submersibles. If the motor is drawing less than full load amperage, then the UC may be set
lower than 80% of FLA for adequate protection. Centrifugal/booster pumps may have to be
set to something higher than 80% of FLA for adequate protection. UC can be set to 0 if UC
protection is not desired. The 777-P2-DEMO examines average current to determine if an
undercurrent trip condition exists. The value must be lower than OC.
SET AT "35".
CUB
- Current Unbalance. SymCom recommends contacting the motor manufacturer for a
specific setting. Current unbalance is calculated the same way voltage unbalance is
calculated (see formula above). Setting CUB to 999 will disable current unbalance and
current single-phase protection.
SET AT "7."