Product

• ThermoFlex Wide I
• ThermoFlex Wide II

Machines affected

All

Component

Drum Vacuum Drive Inverter

Error

Display on Inverter shows External Fault 4 (EF4)

Solution

The EF4 fault appears if the thermistor in the drum vacuum pump has gone open circuit (ie indicating the pump is overheating), or if there is a break in the wiring to the thermistor.

1. Turn the drum vacuum system power off.
2. Remove the drum vacuum controller box cover and the inverter cover (15-1323).
3. Inside the inverter, measure the resistance across terminals SC and S4. With the vacuum pump at room temperature, the resistance should be approximately 200-400 ohms. If it is higher, either the pump has overheated, or there is a break in the wiring.
4. Double check the wiring at terminals 1, 2 and 3 on the green connector P3 (see the wiring diagram inside the controller box cover for reference). Pin 1 should be RED, pin 2 should be BLACK or GREY, and pin 3 should be BLACK heatshrink or GREEN/YELLOW heatshrink.
5. Also check the terminal wiring inside the junction box in the pump enclosure. Terminal 6 should be RED, terminal 7 should be BLACK. See the wiring diagram on the inside cover of the junction box.

This error may also occur due to bad programming. Check parameter n038 to ensure it is set to External Fault (NC). This parameter tells the inverter what to do when an open circuit condition occurs between terminals SC and S4; in this case, trigger a fault condition.
Notes: Once the problem has been corrected, the inverter must be reset by pressing the STOP/RESET button. This should clear the error on the display. If the wiring and programming are OK, then the pump is probably overheating because the cooling fan is not operating. Wait for the pump to cool down, reset the inverter to clear the fault, then run the system and check that the cooling fan runs at the same time.

See also

• Drum Vacuum Controller box wiring diagram: 74-3242A
• Drum Vacuum Pump junction box wiring diagram: 74-3246A
• Drum Vacuum Drive programming instructions: 77-0092A

Technical contact(s)

Ian Skinner

Submitted by

Ian Skinner

Date submitted

04 Jun 2004