- Overcrank (shutdown)
- High Coolant Temperature (shutdown)
- Low Oil Pressure (shutdown)
- Overspeed (shutdown)
- Emergency Stop (shutdown)
- Spare Fault (shutdown or alarm)
Fault Management For 3412 PEEC Engines AND 3412/3500 MUI Engines
There is a degree of severity that is attached to every fault. The degree of severity also describes the response of the control board to the fault. There are two types of faults.
Shutdown - critical
Alarm - noncritical
A shutdown fault tells the control board to shutdown the engine in order to prevent damage to the engine or to the generator. The control board performs the following steps when a shutdown fault is detected.
- The fuel is shut off.
- The shunt trip circuit breaker is opened.
- The corresponding fault indicator is illuminated.
- The optional general alarm relay is activated.
All faults are shutdown faults except the spare fault. The spare fault is not a shutdown fault if the spare fault is set for alarm mode. The "B+" voltage is taken from the system reset input when the remote start switch is opened. Removing the voltage alerts the control board to reset any shutdown faults.
An alarm fault provides an early warning to the operator before a possible future shutdown fault. The only possible alarm fault is the spare fault. The spare fault may be set for the purpose of warning the operator. For an alarm fault, the control board automatically illuminates the spare fault indicator. The control board also activates the optional general alarm relay. Pressing the lamp test switch on the front panel will reset the alarm fault.
The control board receives fault information from internal electronic circuitry and external switch inputs. The internal electronic circuitry decides on faults regarding overspeed and overcrank. The following faults are external switch inputs: low oil pressure, high coolant temperature, emergency stop and one spare fault. When the switches are closed to the battery's negative terminal, the switch inputs react.
After engine start-up, an internal timer immediately delays fault protection. The internal timer is called the fault protection timer ("FPT"). The fault protection timer delays the response to a fault in order to allow engine conditions to stabilize. The amount of delay is factory set for 15 seconds. The "FPT" potentiometer (9) can be used to adjust the delay time. Delay time can be adjusted from 8 to 110 seconds. The fault protection timer is not armed until crank terminate speed is reached.
Note: The "FPT" functions for the low oil pressure fault, the high coolant temperature fault and the spare fault. The "FPT" does not function for the emergency stop fault or the overspeed fault.
The control board provides a fault input that is programmable. This fault input is called the spare fault. The control board may respond to a spare fault condition in two ways.
- The fault may be identified as an alarm fault.
- The fault may be identified as a shutdown fault.
The operator can include the fault protection timer for the spare fault condition. The operator can exclude the fault protection timer ("FPT") for the spare fault condition. The control board will respond in a preselected manner when there is a battery negative signal at the spare fault input.
- Alarm versus Shutdown
- "FPT" versus no "FPT"
On the front panel, the spare fault indicator is yellow for an alarm fault or red for a shutdown fault.
The spare fault input can be used for customer needs or for use at the factory. Optional factory devices that can be connected to the spare fault input are listed below.
- Engine Coolant Loss Sensor
- Overvoltage Relay
- Undervoltage relay
- Ground Fault Relay
- Low Fuel Level Switch
- High Fuel Level Switch
The SW1 switch (1) on the control board is used to set the type of fault. The fault response may be programmed to warn the operator. Also, the fault response may be programmed for engine shutdown. SW3 (7) is used to set the spare fault's fault protection timer. See Testing And Adjusting, "Spare Fault - Adjust" for more information.