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3.1 Power Outage:
Background
Power outage may have occurred during operation. Any power outage in excess
of 250 ms (.25 sec) will cause the control circuit to reset. This can occur in
installations with automatic reset circuit breakers. Electrical disturbances can
also occur from power company interruptions such as lightning storms. This loss
of power will de-energize the contact coils, relays, and solenoids. The loss of
power to the Intellisys power supply (24 VAC) will cause the system to reset to
an off state which causes the displayed message of “Ready to Start”.
Procedure
Power outages can be diagnosed by using power line recording and
measurement instrumentation. A low cost method of measuring this type
occurrence is to utilize a FLUKE 87 recording voltmeter. This meter can detect
the loss of power as short as 100 ms (.1 Sec). By measuring secondary 120
VAC or 24 VAC circuits with the meter set to “VOLTS AC”, 100 ms record mode,
loss of power can be measured. To measure the 120 VAC, connect the meter to
P1 terminal 1 & 10 on the controller. To measure the 24 VAC, connect the meter
to J1 terminal 1 and 2 on the power supply board. To measure the 12 VDC to the
controller, connect the meter set in volts DC to J4 terminal 1 & 2 on the power
supply board.
3.2 Voltage Sag:
Background
Incoming voltage dips below 30% of rated voltage (example 460 VAC nominal =
322 VAC). Any voltage sag in excess of 250 ms (.25 sec) in duration will cause
the control circuit to reset. This can occur in installations with phase unbalance
problems, loss of phase, harmonic distortion, poorly distributed power
management (i.e. undersized step down transformers for application loading),
excessive wire length, and undersized wiring. Electrical disturbances, such as
lightning storms, can also cause voltage sags. The voltage sag will de-energize
the contact coils, relays, and solenoids. The voltage sag to the Intellisys power
supply (24VAC) will cause the system to reset to an off state which causes the
displayed message of “Ready to Start”.
Procedure
Voltage sags can be diagnosed by using power line recording and measurement
instrumentation. A low cost method of measuring this type occurrence is to utilize
a FLUKE 87 recording voltmeter. This meter can detect the loss of power as
short as 100 ms (.1 Sec). By measuring secondary 120 VAC or 24 VAC circuits
with the meter set to “VOLTS AC”, 100 ms record mode, loss of power can be
measured. To measure the 120 VAC, connect the meter to P1 terminal 1 & 10 on
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