Planer Problem - 1980s Wadkin Bursgreen BAOS planer

[Planerproblems]

Hello!

I have a 1980s Wadkin Bursgreen 3 phase planer that I’m trying to run off a single phase power supply. To achieve this, I have wired my single phase power through a 35amp fuse in my garage, into a Transwave static phase converter. I’ve run a cable from this converter into my planer. Here’s a photo of the starter:

Photo 1: https://ibb.co/Lz3crB9



The brown, red, and yellow cables at the bottom of the photo are coming directly from the converter, as is the Earth cable grounded in the top right.

The planer has two motors, one for cutting (3hp) and one for feeding (0.5hp).

The three pairs at the top of the photo are (brown & black), (brown & blue), and (brown & brown). One brown cable from each of the three pairs is connected directly to the cutter motor, as is one of the Earth wires grounded in the top right of the photo. The black, blue and other brown cable that makes up each pair goes to the feeding motor. To isolate the problem I’m having, I’ve disconnected these three wires.

So the current set up is: the brown, red, and yellow cables at the bottom of the photo come directly from the phase converter, the thick Earth cable at the top right of the photo also comes from the phase converter. Then their three corresponding brown cables at the top of the photo go to the cutting motor, and one of the Earth cables in the top right of the photo goes to the cutting motor too.


Now here’s the issue, while I was wiring this in, everything worked correctly. I started the planer and after 1-2 seconds the “Boost” light on the phase converter would switch off, meaning the motor had received enough power and was running correctly. But I think I did something to either a cable or the starter when I was screwing on the front panel, because when I start the planer now, the “Boost” light on the phase converter stays on, and the motor keeps accelerating until it cuts itself out after 30 seconds (the motor overheats). I’ve tried the following:

· Checked every wire for snags/cuts

· Rewired each brown wire at the top of the photo directly into the motor to ensure none are damaged

· Checked the connectors in the starter to make sure there’s no corrosion/that they’re contacting correctly

· Disconnected the three input wires at the bottom of the photo and turned on the phase converter, tested with a phase tester, they all have power in them

· Reconnected the input wires, and then disconnected all wires from the top of the photo and used a phase tester on each, there’s power in all of them

· Reconnected all wires, switched on the phase converter, and before switching on the planer, I tested every connection with the phase converter, every connected registered power when I did this. I then switched on the motor and tested every connection again, this time there was no power in the yellow cable, and no power in the two corresponding wires across from the yellow cable

· I also tried changing the amp dial on the left of the second photo (0-8 amps), the planer didn’t start at 0-1 amps, but did start from 2-8 amps

Photo 2: https://ibb.co/TtJKF2Q



I’m completely at a loss as to what changed while screwing on the face plate, I feel like something must have been damaged and the phase converter isn’t registering the fact that the motor has enough power and that it can cut off the “Boost” function, instead it’s continuing to accelerate the motor until it overheats. I can’t work out what it is, there’s no damage to the wiring that I can see and the connectors in the starter look good.

Any advice anyone could give on this would be really appreciated. Thank you!

Moderators note : inserted uploaded images

 

[kellys_eye]

Middle contact of the top three looks to be very dodgy (arcing?). What state are the rest of them?

 

[Planerproblems]

Middle contact of the top three looks to be very dodgy (arcing?). What state are the rest of them?

Hi! Thanks so much for your reply. I just took a photo of the contacts you mention, here they are:

 

[Bluejets]

Don't know why people bother doing this.
Must end up more expensive and riddled with problems in the end.

 

[kellys_eye]

the phase converter isn’t registering the fact that the motor has enough power and that it can cut off the “Boost” function,

How does it do that? How does it discern between the two motors (feed and cut)? With two motors effectively paralleled - and assuming they are of different ratings - it might detect the switch-on surge of the main (cutting) motor and calculate the power that it requires BUT when the other (feed) motor starts up it 'sees' an increased demand and tries to make the smaller motor draw the same power as the main motor?????

Does the system work ok with just one motor connected?

Sure there isn't a problem in one of the phases (yellow)?

Any motor capacitors in there - perhaps on the smaller motor?

 

[Planerproblems]

How does it do that? How does it discern between the two motors (feed and cut)? With two motors effectively paralleled - and assuming they are of different ratings - it might detect the switch-on surge of the main (cutting) motor and calculate the power that it requires BUT when the other (feed) motor starts up it 'sees' an increased demand and tries to make the smaller motor draw the same power as the main motor?????

Does the system work ok with just one motor connected?

Sure there isn't a problem in one of the phases (yellow)?

Any motor capacitors in there - perhaps on the smaller motor?

c
I'm unsure how it detects when the cutting motor is up to full speed, but the phase converter manual advises that the smaller motor (feed motor) should only be switched on after the cutting motor has started running - I think it does draw power away from the cutter but it only takes a small amount to run the feed motor. The cutting motor is 3hp, and the feed motor is 0.5hp. The manual for the phase converter is here: https://transwave.co.uk/storage/downloads/9/STC Static Converter Literature & Manual 2021.pdf it states "Starting Surge: All TRANSWAVE Converters automatically control the motor starting surge, maintaining the surge until the motor has attained its full running speed irrespective of time taken. The operator need not leave the driven machine to reset the converter for starting."

I disconnected the feed motor to see if the problem might be with the feed motor connections, unfortunately the problem still persists with just the single cutting motor connected. I'm pretty sure the motor is overheating because the surge/boost isn't getting turned off. When it worked correctly the boost would switch off after 1-2 seconds and the motor would run perfectly and wouldn't overheat. Now it overheats and shuts itself off after 30 seconds.
Neither motor has a capacitor. How should I check for problems with the yellow phase? When the 3 inputs are disconnected from the motor, I switch on the phase converter and the phase tester registers power in each cable (brown, red, yellow), it registers power in all three when they're connected to the starter switch too. But when the motor is switched on, it doesn't register power on the yellow connection, or the two smaller corresponding wires across from the yellow connection which are going to the motors. Does this indicate a break in a circuit? Or is this correct for a phase converter? (ie, is this showing that the sudo "3-phase" connection has correctly switched off after the motor has started to run?)
Thanks again for your help!

 

[kellys_eye]

I suspect - but can't confirm - that the inverter can detect power in each of the phases. It may be that the detector in the yellow phase is faulty(?) therefore the unit is unable to recognise a full power situation and keeps feeding power. That said, if one phase is missing I don't see how your motor can achieve full rotational speed (or even overspeed) without it?

Try connecting only the feed motor (or another 3-phase motor you might have available?) to see if it does the same with a different load.

The phase cnverter isn't 'magical' - it does what it says on the box and converts 1-phase to 3-phase and you can (should) treat the output as a simple 3-phase source supply. Any 'magic' comes with the units ability to regulate the feed current to prevent overload - something normally dealt with by fuses/circuit breakers in a 'real' 3-phase situation.

 

[Planerproblems]

I suspect - but can't confirm - that the inverter can detect power in each of the phases. It may be that the detector in the yellow phase is faulty(?) therefore the unit is unable to recognise a full power situation and keeps feeding power. That said, if one phase is missing I don't see how your motor can achieve full rotational speed (or even overspeed) without it?

Try connecting only the feed motor (or another 3-phase motor you might have available?) to see if it does the same with a different load.

The phase cnverter isn't 'magical' - it does what it says on the box and converts 1-phase to 3-phase and you can (should) treat the output as a simple 3-phase source supply. Any 'magic' comes with the units ability to regulate the feed current to prevent overload - something normally dealt with by fuses/circuit breakers in a 'real' 3-phase situation.

Hi kellys_eye thanks for your advice on this. I have a second phase converter (same model except it's a 7hp one instead of a 3.5hp one), I tried both today and I'm getting the same result, this makes me think that the issue isn't with the converter. I also rewired the 3-phase plug going from the converter into the planer to ensure those cables are all okay, I'm still getting the same result. I tried each 3-phase motor (cutter & feed) individually, and both together, the same problem is happening, so I don't think there's an issue with an individual motor, the only constant in each test is the starter. I took the starter apart today, cleaned it, ensured all connections are correct, but the problem still persists. There is a capacitor in the starter which I'll test with a multimeter tomorrow, failing that I can't think of what else it could be.