FORM 160.77-O2
ISSUE DATE: 11/15/2011
SECTION 5 - DISPLAY MESSAGES
JOHNSON CONTROLS
121
5
• 3300 Volt Starters – 3739 VAC
• 2300 Volt Starters – 2606 VAC
Pri SSS Fault: Low Line Voltage
The incoming line voltage has dropped below the
threshold as detected at the signal applied to the Con-
troller board at TB10. The threshold is as follows:
• 4160 Volt Starters – 3370 VAC
• 3300 Volt Starters – 2673 VAC
• 2300 Volt Starters – 1863 VAC
Pri SSS Fault: Failed SCR
This fault indicates an open or shorted SCR has been
detected. The controller board looks at line voltage
and motor current, and determines if an SCR is open
or shorted based on analysis of the voltage and current
waveforms and knowing what SCR device should be
turned on at any given time. The controller does not
indicate which SCR was detected to have a problem.
It is necessary to check the devices with an ohmmeter
and/or gate/hi-pot tester. Refer to form 160.00-M5 for
additional information.
Pri SSS Fault: High Temperature
This fault is generated when the MV SSS heatsink tem-
perature exceeded 194°F (90°C), and a Klixon® de-
vice on one of the 3 stacks has opened its circuit.
Pri SSS Fault: Serial Receive Error
This fault is generated when there is a network timeout,
and no Modbus communications for more than 60 sec-
onds.
Pri SSS Fault: Power Supply Failure
This fault is generated when the unit detects undercur-
rent, one of the phases has dropped below 10% FLA
for 2 cycles, or the Motor Current dropped to below
25% FLA for 1/2 second while running. This fault is
inhibited for the first 4 seconds of starting, and until all
phase currents have reached 25% FLA.
Pri SSS Fault: Phase Rotation
This fault is generated when the incoming phase rota-
tion is not ABC.
Pri SSS Fault: Contactor Fault
Bypass or In-line Contactor Fault, aux. contacts do
NOT match contactor status.
Pri SSS Fault: Ground Fault
The ground fault current has been determined to have
exceeded 50% of motor FLA for 3 seconds. There is
no device measuring current to ground. This is done by
looking at all three motor currents, and calculating the
instantaneous sum of all three. Recognize that at any
given time, the current passing in the direction toward
the motor must equal any currents coming back from
the motor in the other phases. The net sum of all three
instantaneous currents (with attention to polarity) is al-
ways zero. If at any time the sum is not zero, this would
indicate that some current passing toward the load is
not returning to the starter, but is leaking off to ground.
Pri SSS Fault: Control Board
This message is generated when the MV SSS Control
board has a failure, and the Control Board needs re-
placed.
Pri SSS Read Fail
The MV SSS Logic/Trigger Board has shut down the
chiller but the Control Center has not yet received the
cause of the fault from the MVSSS, via the serial com-
munications link. The MVSSS shuts down the chiller
by opening the Motor Controller MVSSS Stop Con-
tacts. The Control Center then sends a request for the
cause of the fault to the Logic/Trigger Board over the
serial communications link. Press the RESET button to
clear the message.
Pri SSS Write Fail
This message is generated when the checksum test
failed at power up. Check to see that the proper pro-
gram is loaded to the controller board. Press the RE-
SET button to clear the message.
Pri SSS Read Trip
After communications have been established, if the
Control Center does not receive a reply within 3 con-
secutive read attempts, a shutdown is performed. This
same shutdown is performed if the MVSSS does not
receive a response from the control center after 3
consecutive read attempts to communicate with the
Control Center after INITIALIZATION has been suc-
cessfully completed. The Control Center attempts to
establish communications until successful. Press the
RESET button to clear the message.
To Next Page
Loading...
Need help?
General
