[mflux_gamblej]

I repaired the spindle drive on my Interact 1 mk2, with the help of some folks here. I was programming the software axis limits, trying out some programming, and decided that I would turn the coolant on.

I spun up the spindle, put the coolant switch to the flood (clockwise) position, and bam! lights out.

Now the machine doesn't supply any power (0 V from L to Gnd) to the Heidenhain 151 B controller. When you turn the machine on, the controller doesn't light up of course, so nothing happens.

I've checked all of the fuses that I can find on the machine, all that I know about are not broken (these are the large 'main' fuses in the power supply cabinet [right side of machine], and the fuse in the back of the heidenhain 151).

I looked into the coolant sump, and the son of a B that worked on the machine last didn't even mount the pump inside the sump. It was short circuited for sure (pump motor / capacitor was upside down in the coolant!!) in a pile of coolant and metal filings.

I am learning some lessons about (used) machine commissioning the hard way.

please help!

Thanks guys,

- Joe

[mflux_gamblej]

I read that there might be a fuse or fuses behind the big red isolator switch (the mains supply disconnect switch).

Does anyone have experience with these fuses?

I'll check it out when I get home tonight and report back, but some advance discussion would sure help.

- Joe

[mflux_gamblej]

There are three small fuses (0.5 A, 1.0 A, 2.0 A) on the large terminal block in the power supply cabinet (right hand side cabinet). The 0.5 A fuse was blown. I replaced that, and not to my surprise, this didn't solve the issue.

There isn't any power (expected 120V) being supplied to the heidenhain 151 B. The controller's fuses are all OK.

I found more fuses in the power cabinet (right hand side cabinet) on the transformer 'T1.' These are all 10 A fuses. They're all intact.

At the moment I am suspicious of 'Overload 3,' which is in the supply cabinet. The output voltage is ~ 1 volt on each of the three rails.

I don't seem to be able to operate the overload though. The red 'test' tab doesn't do anything, and the blue 'reset' button doesn't really do anything either. I've pressed both of these buttons with the power applied to the machine.

Does anyone have experience with overloads failing? This is a Klockner-Moeller EZ00 overload (the 200-6 model with 4 to 6 amps selectable) Is there a fuse inside the overload?

[kongzai]

Don't "guess", it's a waste of time.
Work by the correct way - get a multimeter. You know there should be a 120V go into the controller, so start from there. If you don't have the wiring diagram of the machine, look up into the cabinet for the transformer that should supply the 120V. Using the meter, make sure that transformer gets the 415V supply at the input and 120V at the output. If you can't get 415V supply, trace it up stage, and if you can get a 120V on the output, trace the wiring until you get to the next one, maybe a fuse or smth else that cuts the supply.

Overload relays should not be the problem, if any of them trip, they should cut the supply to motors or pumps or give alarms to the control, but NOT cutting the 120V supply for the controller.

[csg67]

TNC151B documentation (See: "Installation and interface description")

[mflux_gamblej]

It turned out to the CFU1 which is the fuse that I replaced. It blew again on powering up the machine. I installed a slow blow 500mA fuse (instead of the fast action type) and the fuse does not blow when you close the isolator.

A note on rotary phase converter supply / 3 phase wye configuration. I did not realise that the voltage to ground is NOT 240v for each leg. only one leg shows 240v to ground. That is because ground is not the lowest potential.

The three phases are 240v apart from eachother. So it should be L1 to L2, L1 to L3, and L2 to L3 are all 240v (i.e. 240v three phase).

Measured to ground, in my case, L1 to Gnd and L2 to Gnd are 120v, L3 to Gnd is 240v.

The fuse CFU1 is located on the main terminal block along the left side of the power supply cabinet.

Problem solved!

Although, I'll need to rebuild / clean up my coolant sump, pump motor and start cap.

I intend to use a 'fogbuster' type droplet coolant system in the mean time to keep my garage clean.


Thanks again for your input. Kongzai's pep talk put me on back on the systematic path to success.

- Joe

[mflux_gamblej]

There are three small fuses (0.5 A, 1.0 A, 2.0 A) on the large terminal block in the power supply cabinet (right hand side cabinet). The 0.5 A fuse was blown. I replaced that, and not to my surprise, this didn't solve the issue.

There isn't any power (expected 120V) being supplied to the heidenhain 151 B. The controller's fuses are all OK.

I found more fuses in the power cabinet (right hand side cabinet) on the transformer 'T1.' These are all 10 A fuses. They're all intact.

At the moment I am suspicious of 'Overload 3,' which is in the supply cabinet. The output voltage is ~ 1 volt on each of the three rails.

I don't seem to be able to operate the overload though. The red 'test' tab doesn't do anything, and the blue 'reset' button doesn't really do anything either. I've pressed both of these buttons with the power applied to the machine.

Does anyone have experience with overloads failing? This is a Klockner-Moeller EZ00 overload (the 200-6 model with 4 to 6 amps selectable) Is there a fuse inside the overload?

there are Not fuses in the isolator switch as another post referred to.

[mflux_gamblej]

The motor being upside down in (5-10 year old?) coolant/oil/metal sludge definitely shorted out in this case. I don't know if the motor windings saw Gnd here.

After taking the lid off of the motor electrical connections box, the inside is totally dry and in good shape.

I tested the start cap with my multimeter, it read close to the spec on the side.


So, where exactly the short happened, I don't know. After cleaning the motor up, I tested the pump (120v, 1 phase) in a bucket of water - it ran no problem.

I re-assembled the pump into the coolant sump, and I'm off and running my flood coolant system.


As a side note: clean out your coolant sump every year, and keep a close eye on tramp oil (way oils, etc that make their way into the sump). Also, make sure that any gratings and filters are keeping chips out of the sump. Cleaning up the sludge from underneath and in back of a 25 year old bridgeport CNC machine was one of the worst tasks I've done in a long time. It was likely dangerous too - it certainly was serious industrial waste. That was a good 4 hours of hell.