Engine Control Module (ECM) Faults May Not Reset On 3500B Or 3500 EUI Gensets Equipped With EMCP II Or EMCP II+ Caterpillar

Problem:

When equipping EMCP panels with a Pin 6 to Pin 9 jumper on the engine control switch (ECS) to power the control panel when the ECS is in the OFF/RESET position, this will keep the engine control module (ECM) powered at all times. If the ECM is not allowed to power cycle when the ECS is in the OFF/RESET position, any potential shutdown faults or E stop inputs will not be reset. This will then disable the engine from being restarted.

Solution:

The timer will still provide a means to annunciate a "Not In Auto" alarm without generating additional alarms caused by a communications loss between the generator set control (GSC) and ECM. This will temporarily cause the ECM to reset any potential fault conditions to avoid a restart problem. Set the dials and connection to the settings in the tables below.

Procedure:

The normally closed timer (Allen-Bradley #700-FSM3UU23) contacts (Pin 15 and Pin 16) should be connected between RM1 and RM2 of the GSC. The contact keeps the GSC powered up even when the ECS is in the OFF/RESET position. The GSC must remain powered in the OFF/RESET position in order to produce a "Not In Auto" alarm. The timer trigger ECS is in the OFF/RESET position. The timer was setup as a "One Shot Trigger" (Setting C). This setting causes the normally closed contact to open immediately once power is applied. When the contacts open, the GSC is powered down after the engine comes to a complete stop (RPM=0). After the time has expired (set at 40 seconds on the timer), the contacts will close again and repower the GSC. The timer was set to 40 seconds to account for the coast down time delay of the engine plus reset time. This will clear any fault in the engine ECM and the GSC.

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