Section 7: Faults - Fault Finding; On Board Fuse Blows; Testing 24Vdc; Testing Rcd / Rcbo On 110Vac Safety Circuit - ECD 100-194 EN81 Manual

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Section 7: Faults – Fault finding.

There are 2 fuses mounted on the controller board.

The 2A fuse protects the 5Vdc supply to all the logic on board.

The 4A fuse protects the 24Vdc supply.

If 2A (5Vdc) fuse blows check that the 6V Zener diode is not short circuited. (return for repairs)

If 4A (24Vdc) fuse blows.

 Test for fault on 24Vdc circuits (inputs/outputs)

 Remove all external plugs except 18Vac and 10Vac

 Replace fuse. If 4A fuse still blows, check that the 30V Zener diode is not short circuited. (return for

repairs)

 If fuse does not blow plug in external inputs/outputs one plug at a time and test for external fault.

Ensure 0V and +24V are free from other voltages.

Ensure 0V is not connected Earth.

High voltages may be superimposed on 0V and +24V lines as no reference to ground exists. See Warning 1.2.14

 Turn the meter to the HIGH VAC range.

 Meter between 0V and Neutral. (Should be 0V)

 Meter between 0V and L2A (if applicable). (Should be 0V)

 Meter between +24V and Neutral. (Should be 0V)

 Meter between 0V and +24V. (Should be 24Vdc)

If 24Vdc is low or unstable, check large capacitor C69 on PCB. This capacitor may have been hit or knocked,

which can break off one of the legs soldered into the PCB. A gentle twist will reveal if one leg has broken. If so,

replace the capacitor

To test the trip operation of an RCD / RCBO supplied with a 110VAC safety circuit, place a 1.2K ohm resistor

between the load side of the RCD / RCBO and earth.

Check door disable switch DDO on PCB is off

See Inputs-Outputs, DDO

Ensure the MSU slowing input is activated before the Top Slowing Limit (TSL) at the top floor

Ensure the MSD slowing input is activated before the Bottom Slowing Limit (BSL) at the bottom floor

See prints for magnet and limit positions

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