electricalhelper-3ph-troubleshooter

Turn the power off with the breaker or disconnect and lock out and tag out according to your specific facility requirements.

Does the ohm meter read '0' as shown above for both fuses?

YES

If your volt-ohm meter has a manual selector switch, place the meter in the ohm meter position with the selector switch on the meter. if your meter has an automatic selector you just need to be sure it is on the ohm meter setting and that the meter leads are in good shape and in the right meter jacks.

Replace the fuse or fuses, restore the power and press the ‘Green P/B’ to continue.

Restore the power and press the ‘Green P/B’ to return to the previous step to retest.

NO

Is the voltage at the appropriate level? In most cases, where a control transformer is utlized the secondary voltage will be 120 volts.

YES

If there is no secondary voltage between (I and J) with primary voltage applied, the control transformer is bad.

Back

Check the voltage between (K and J) noting the voltage. Please complete the steps in the yellow box and then follow the below steps.

Is the voltage at the appropriate level? In most cases, where a control transformer is utlized the secondary voltage will be 120 volts.

Yes

If you have proper voltage between (I - J) and not between (K-J), the secondary fuse is bad.

No

Back

Does the ohm meter read '0' as shown above for both fuses?

YES

Replace the fuse or fuses, restore the power and press the ‘Green P/B’ to continue.

Restore the power and press the ‘Green P/B’ to return to the previous step to retest.

NO

The voltage between (M-U) should be the same as the voltage between (K-J) in the last test.

YES

No

Click Here For A Schematic Drawing.

Is the voltage at (M-U) the same as (K-J)?

Back

Click Here For A Pictorial Drawing.

The voltage between (M-U) should be the same as the voltage between (K-J) in the last test.

YES

No

Is the voltage at (M-U) the same as (K-J)?

Is the ohm meter reading low (only several ohms)?

YES

Back Up One Step

Press the ‘Green P/B’ to continue with the next test.

Back

If the reading is high or infinite, Press NO P/B.

NO

Is the ohm meter reading low (only several ohms) in each of the steps above?

YES

Take the necessary action to make sure the resistance path in each of the two steps above is near (0).

Return to previous test.

NO

Place the leads of the ohm meter between (U-J) and take the reading. Should be (0) or only several ohms.

Is the ohm meter reading low (only several ohms) in the step above?

YES

Take the necessary action to make sure the resistance is near (0). Clean & repair the (Stop P/B) or replace it.

Continue With The Next Step.

NO

Click Here For A Schematic Drawing.

Is the ohm meter reading zero ohms in the step above?

YES

Take the necessary action to make sure the resistance is near (0). Clean & repair the (Stop P/B) or replace it.

Continue With The Next Step.

NO

Click Here For A Pictorial Drawing.

The voltage between (M-T) should be the same as the voltage between (M-U) in the last test.

YES

No

Click Here For A Schematic Drawing.

Is the voltage at (M-T) the same as (M-U)?

T

Back

The voltage between (M-T) should be the same as the voltage between (M-U) in the last test.

YES

No

Click Here For A Pictorial Drawing.

Is the voltage at (M-T) the same as (M-U)?

Is the ohm meter reading (should be zero) in the step above?

YES

Take the necessary action to make sure the resistance is near (0). Try reseting the overload by pressing the overload reset button.

NO

If necessary the overload block may have to be replaced.

Click Here For A Schematic Drawing.

Continue With The Next Step.

Is the ohm meter reading (should be zero) in the step above?

YES

Take the necessary action to make sure the resistance is near (0). Try reseting the overload by pressing the overload reset button.

Continue With The Next Step.

NO

If necessary the overload block may have to be replaced.

Click Here For A Pictorial Drawing.

Place the leads of the ohm meter between (M-P) and take the reading. Should be (0) ohms when to Start P/B is pressed and held in.

Is the ohm meter reading zero in the step above? Should be (0) with the Start P/B pressed and held in. Should be infinate when the Start P;B is released.

YES

Take the necessary action to make sure the resistance is near (0). The Start P/B can cause problems when its contacts become dirty and oxidized

Restore the power and Continue.

NO

Click Here For A Pictorial Drawing.

Is the ohm meter reading zero in the step above? Should be (0) with the Start P/B pressed and held in. Should be infinate when the Start P;B is released.

YES

Take the necessary action to make sure the resistance is near (0). The Start P/B can cause problems when its contacts become dirty and oxidized

Restore the power and Return to previous test.

NO

Click Here For A Pictorial Drawing.

The voltage between (P-Q) should be the same as the voltage between (M-T).

YES

No

Click Here For A Schematic Drawing.

Is the voltage at (P-Q) the same as (M-T)?

With proper voltage applied between (P-Q) the starter should be energized. If not your starter has a bad coil. If the starter drops out as soon as the Start P/B is released, the auxiliary contact (R-S) is faluty.

Caution:

The starter will energize during this test if everything is performing normally.

Back

The voltage between (P-Q) should be the same as the voltage between (M-T).

YES

No

Click Here For A Pictorial Drawing.

Is the voltage at (P-Q) the same as (M-T)?

With proper voltage applied between (P-Q) the starter should be energized. If not your starter has a bad coil. If the starter drops out as soon as the Start P/B is released, the auxiliary contact (R-S) is faluty.

Caution:

The starter will energize during this test if everything is performing normally.

You will need to submit your First Name and Email Address, If you would like to receive your recorded information.

Is the voltage at the appropriate level? 208 volts on a 208 volt 'Y' system. 240 volt on a 240 volt 'D' system. 480 volt on a 480 volt 'D' system. (+ -) 10% on most power distribution systems.

YES

No

Notice: Not all combination disconnect starter units have control transformers or control fuses. The control fuses are only required on units where the control wiring is not solely contained within the starter enclosure.