JOHNSON CONTROLS
135
SECTION 2 – OPTIVIEW CONTROL CENTER
FORM 160.79-O3
ISSUE DATE: 11/09/2018
2
“MOTOR CONTROLLER #1 – CONTACTS
OPEN”
A motor controller protection device for compres-
sor #1 has initiated a shutdown (both compressors).
Normally closed contacts of locally installed external
motor protection devices (connected between TB6-15
and TB6-53) and the normally closed “CM” contacts
of CM-2 Board #1 (connected between TB6-53 and
TB6-16) form a safety circuit in series with the starter
run signal. If any of these contacts open and remain
open for at least 3 seconds, this shutdown is initiated.
The CM-2 board opens its contacts when it detects a
motor current overload condition on motor #1. When it
detects this condition, the Overload LED on the CM-2
board illuminates and the board’s CM contacts open
to initiate the shutdown. The LED will remain illumi-
nated and the contacts will remain open until the Reset
button on the CM-2 board is pressed. The chiller will
automatically restart when the contacts close.
If compressor #1 is locked-out using the Lockout key
on the Capacity Compressor Cycling Screen, this fault
does not cause compressor #2 to shutdown or prevent
it from starting. When this fault occurs on a locked-out
compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out
compressor. The condition must be corrected prior to
the lockout being removed from the compressor. If it
is not, the warning condition will revert back to a shut-
down as soon as the lockout is removed and will cause
the chiller to trip.
“MOTOR CONTROLLER #2 – CONTACTS
OPEN”
A motor controller protection device for compres-
sor #2 has initiated a shutdown (both compressors).
Normally closed contacts of locally installed external
motor protection devices (connected between TB6-15
and TB6-54) and the normally closed “CM” contacts
of CM-2 Board #2 (connected between TB6-54 and
TB6-82) form a safety circuit in series with the starter
run signal. If any of these contacts open and remain
open for at least 3 seconds, this shutdown is initiated.
The CM-2 board opens its contacts when it detects a
motor current overload condition on motor #2. When
it detects this condition, the Overload LED on the
CM-2 board illuminates and the board’s CM contacts
open to initiate the shutdown. The LED will remain
illuminated and the contacts will remain open until the
Reset button on the CM-2 board is pressed. The chiller
will automatically restart when the contacts close.
If compressor #2 is locked-out using the Lockout key
on the Capacity Compressor Cycling Screen, this fault
does not cause compressor #1 to shutdown or prevent
it from starting. When this fault occurs on a locked-out
compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out
compressor. The condition must be corrected prior to
the lockout being removed from the compressor. If it
is not, the warning condition will revert back to a shut-
down as soon as the lockout is removed and will cause
the chiller to trip.
“MOTOR CONTROLLER #1 – LOSS OF CUR-
RENT”
The chiller (both compressors) shutdown because the
compressor #1 motor current has decreased to < 10%
FLA for 25 continuous seconds while it was running.
This could be caused by the starter de-energizing or a
defect in the motor current detection circuitry to the
Control Center. The motor current value is provided by
CM-2 board #1 to the Microboard. The chiller will au-
tomatically restart at the completion of “Coastdown”.
“MOTOR CONTROLLER #2 – LOSS OF CUR-
RENT”
The chiller (both compressors 0 shutdown because
compressor #2 motor current has decreased to < 10%
FLA for 25 continuous seconds while it was running.
This could be caused by the starter de-energizing or a
defect in the motor current detection circuitry to the
Control Center. The motor current value is provided by
CM-2 board #2 to the Microboard. The chiller will au-
tomatically restart at the completion of “Coastdown”.
“MOTOR CONTROLLER #1 – POWER FAULT”
A motor controller protection device has shutdown the
chiller (both compressors). Normally closed contacts
of locally installed external motor protection devices
(connected between TB6-15 and TB6-53) and the nor-
mally closed “CM” contacts of CM-2 Board #1 (con-
nected between TB6-53 and TB6-16) form a safety cir-
cuit in series with the starter run signal. If any of these
contacts open and reclose in less than 3 seconds, this
shutdown is initiated. The CM-2 board opens its con-
tacts and recloses them in less than 3 seconds when it
detects a motor current Power Fault condition on mo-
tor #1. A Power Fault condition occurs when the motor
current drops below 10% FLA. This protects against
potential compressor damage due to rapid opening
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