IB140012EN
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Instructional Booklet
Effective: March 2021
Page
29
Operation and Maintenance Manual,
Automatic Transfer Switch Controller, ATC-900
6.3 General Switch Problem Solving
This section explains basic troubleshooting for Transfer Switches.
The particular switch instruction booklet should be used to trou-
bleshoot. A basic problem solving effort is the first step to take
prior to calling for assistance. Frequently, the effort will success-
fully address most problems encountered. The problem solving
procedure is presented in the following sections as observed Prob-
lem Symptoms and one or more possible Solution Steps. All of
the steps presented may not apply to all transfer switches,
depending upon the logic.
Remember, only qualified individuals
familiar with the transfer switch equipment and the system in
which it is applied should attempt these problem solving proce-
dures.
If a problem persists after having completed the problem solving
procedure, contact an Eaton representative for further assistance.
When calling for assistance, the following is the minimum infor-
mation required to properly address the need:
Note:
If a message is flashing on top of the display and the fault is
removed, simply press "Help" and then "Enter" and the message will be
removed.
1. General Order Number (GO#) of transfer switch, plus related
Item Number;
2. Catalog Number of transfer switch;
3. Actual location of transfer switch (type of facility, address,
etc.);
4. Style number of the controller;
5. Company, name and position of individual representing com-
pany;
6. Basic description of situation as it exists; and
7. Any results of problem solving steps taken and/or readings
taken from the events and summaries.
Table 9. Troubleshooting Guide (Cont.).
SYMPTOM
PROBABLE CAUSE
POSSIBLE SOLUTION(S)
BP status lamp is on or blinking.
Lamps need to be off when both BP contactors are racked in.
Rack contactor(s) in
Plant exerciser (PE) failed to exercise.
Incorrect date or time setting.
Incorrect setpoint programmed for PE day and/or time.
Generator voltage and/or frequency did not become available
within 30 seconds of engine starting.
Verify real time settings for Time/Date.
Re-program PE day and/or time setpoint.
Verify voltage and/or frequency with multi-meter. Check programmed setpoint val-
ues. Check engine maintenance.
Controller Displays "Safety Interlock – Trans-
fer Inhibited"
Bypass contactor Door(s) is open (red lamp is blinking), Contac-
tor(s) is not locked in (Statis lamp is on), Monitor Mode (Unit is in
manual mode).
Close the door(s), assure contactor(s) is locked in, turn top user switch to auto-
matic.
Unit displays “Lockout.”
No contact closure at Lockout programmed input.
Verify Lockout input circuit is closed.
Unit displays “INHIBIT”.
No contact closure at Emergency Inhibit programmed Input.
Check Emergency Inhibit Wiring.
Red Door lamp Flashing.
Close and latch doors.
For the contactor bypass, the door(s) is open and will cause the switch to not be in
automatic.
Unit displays an S1 open or close error.
Source 1 circuit did not open when it was commanded to open.
Source 1 circuit did not close when it was commanded to close.
S1 Aux Close contacts did not open when Source 1 opened.
S1 Aux Close contacts did not close when Source 1 closed.
Check Source 1 circuit trip wiring. Press "Help" then "Enter" push-buttons to clear
message.
Check Source 1 circuit wiring. Press "Help" then "Enter" push-buttons to clear
message.
Check S1 Aux Close control input wiring on on J6-1,2. Press "Help" then "Enter"
push-buttons to clear message.
Check S1 Aux Close control input wiring on on J6-3,4. Press "Help" then "Enter"
push-buttons to clear message.
Unit displays an S2 open or close error.
Source 2 circuit did not open when it was commanded to open.
Source 2 circuit did not close when it was commanded to close.
S2 Aux Close contacts did not open when Source 2 opened.
S2 Aux Close contacts did not close when Source 2 closed.
Check Source 2 circuit trip wiring. Press "help" then "enter" push-buttons to clear
message.
Check Source 2 circuit wiring. Press "help" then "enter" push-buttons to clear
message.
Check S2 Aux Close control input wiring on J6-1,2. Press "help" then "enter"
push-buttons to clear message.
Check S2 Aux Close control input wiring on J6-3,4. Press "help" then "enter"
push-buttons to clear message.
NOTICE
WHILE PERFORMING TESTING, IF AN UNDESIRED OR UNDOCU-
MENTED RESULT OCCURS, FIRST CONTACT THE LOCAL GENSET
DEALER. IF THE RESULT IS NOT CORRECTED, CONTACT THE
EATON ATS TECHNICAL SUPPORT AT 1-877-386-2273.
DANGER
HAZARDOUS VOLTAGES IN AND AROUND TRANSFER SWITCH
EQUIPMENT DURING THE PROBLEM SOLVING PROCESS CAN
CAUSE PERSONAL INJURY AND/OR DEATH. AVOID CONTACT
WITH ANY VOLTAGE SOURCE WHILE PROBLEM SOLVING. USE
LOCK-OUT TECHNIQUES TO ASSURE POWER IS REMOVED.
WARNING
ONLY PROPERLY TRAINED PERSONNEL FAMILIAR WITH THE
TRANSFER SWITCH EQUIPMENT AND ITS ASSOCIATED EQUIP-
MENT SHOULD BE PERMITTED TO PERFORM THE PROBLEM SOLV-
ING FUNCTION. SPECIFICALLY, ONLY PERSONS CLASSIFIED AS
QUALIFIED UNDER FAILURE, TO UTILIZE QUALIFIED PERSONNEL
(UNDER NFPA 70E) SHOULD WORK ON EQUIPMENT. IF NOT, IT
COULD RESULT IN PERSONNEL INJURY AND/OR DEATH.
