RDOL Testing Without Motor

Beg, steal or borrow a Phase Sequence Indicator. Here's a fancy Fluke one, other makes and types are available, some with just a couple of LED direction indicators.

oh ok so basically i require some sort of instrument for this right. So either motor has to be there or a phase sequence indicator. Nothing we can easily get?

Fractional horsepower 3Ø motors can be obtained overnight from any number of vendors. Most have so many of them that they will sell them just to get rid of them. Is there anything easier than that?

Re: "So either motor has to be there or a phase sequence indicator. Nothing we can easily get?"

If I had to test this, and didn't have a motor or a phase sequence indicator, I'd do something like this (very carefully):

I'd rig up something to provide control power to the RDOL starters (one at a time is fine) put not provide the "real power" for the power circuit. Then do continuity tests (while looking at the drawings) to confirm that two leads are interchanged by the starter when switched to the reverse run condition.

I'd prefer to test with a real load of some sort, to watch for anything unusual (arcing, vibration of contacts, ???), but such testing could confirm the wiring is correct. (Note that a phase sequence indicator will not provide a load test either.)

If you have a multimeter, you can check the voltage difference from Main contactor o/p to Reverse & forward contactor o/p: from the voltage difference, you'll be able to understand about proper function of Revrse-forward function.

Dear member,

I case you do not have a phase sequence meter. Then I can suggest a cumbersome procedure.

first connect only 'R' phase supply at the input. switch on the starter, I am assuming that the control supply is available. Check at the output end if the supply has moved to a different phase. this you can check with a multimeter. Carry out this exsercise with Y and B phase. If the output shift in one of the phase only then the wiring is alright.

S. V. Iyer

Mark yr outgoing feeders as X,Y,Z.Let yr supply be L1,L2,L3 or R,Y,B.After connecting yr power and control cct for forward and reverse,use continuity test to ensure that in forward direction,L1 reads to X,L2 reads to Y,L3 reads to Z.Stop the forward direction,then start the reverse direction.In the reverse direction,ensure that L1 reads to X,L2 reads to Z,L3 reads to Y,or L1-Z,L2-Y,L3-X, OR L1-Y,L2-X,L3-Z.

Do not operate the power cct,but use only the control cct for yr test.In forward and reverse,only two lines are interchanged,while maintaining one line for best and easy practice.