[paparandy]

Hi All, Recently purchased a Bridgeport Series I R2E3 and I'm trying to get it running. I have powered it up and the controls were working but had an error light on. Things were going good and I was able to move the X & Y around and then tried to home it in, X went all the way to the right side of the machine and Y went forward. They both stopped and then all the power to the controller went away. I now have Logic Board PC-7095-G (located by the Z servo motor) that has 2 fried voltage regulators and at least a hand full of fried diodes. The fuse on the board did not blow. I have 120volts going into the board(#12 & #14) but nothing coming out. I should have 12volts going out to the controller. Before I replace or repair this board I'm wondering if anyone knows what may have caused this to happen. I'm also a little confused on what power I actually have from my incoming service. I have been under the assumption that I have 208volt 3 phase. I have 240volts at L1,L2 &L3 at the machine. At the service panel the same but if I measure from the neutral to the wild leg I get 213volt. The machine is wired up as 230volt. Any thoughts? Help would be greatly appreciated.

paparandy

[Newby2]

First off, you need NOT be concerned with the voltage from each of the 3 legs to ground (neutral). You are dealing with a 3 phase machine. To simplify this, look at you power coming into your house... you have 3 wires, L1, L2, and ground. Between L1 and ground, you have 110-120 volts, between L2 and ground, the same, but between L1 and L2, you have 220-240 volts. That is how you get your toaster,(110 V) and your water heater (220 V) to work off the voltage coming into your house.
With 3 phase, you have a completely different animal. 3 ph does NOT use a ground (neutral) to control the voltage to the various components of the machine. They use transformers to change the voltage to that required for the various controls.
With that in mind, before you initially turned the power on to the machine, you should have verified the voltage to the machine on L1, L2, and L3.
You mentioned you thought you had 208V, 3 ph but the machine was wired for 240V 3 ph. Now you have a bunch of fried parts....not to be a smart a**, but DUH!!!!
If all holds true, there should be a main transformer (T1) that has various taps for the incoming voltage...to give the correct output voltage for the controls. If you apply 240V to a transformer that is connected for an incoming voltage of 208V, the resulting output voltage of that transformer will be in excess of that required for the controls of the machine resulting in...OOPS....black smoke and....damn....fried parts!
Again, when dealing with 3 ph, do NOT be concerned with the voltage between L1, L2, and L3 to ground (neutral).
Steve

[UKRobotics]

Sorry to go off topic here but I have always wondered about this .. you say toasters are 110v and water heaters 240, and you get the 240 by connecting phase to phase rather than phase to neutral , does this mean every house in the USA has 3 phase electricity as standard ?

Here in the UK every house has 240v single phase and you have to pay a lot of money to get 3 phase put in. 3 Phase is then 240v per leg and 415v phase - phase.

[Newby2]

Perhaps there is a langage barrier. The typical US home only has single phase power, and as you, we pay a premium for three phase.
Perhaps the misunderstanding came from calling the 2 hot leads L1 and L2, but here in the US that is the norm. L1 to ground = 110 V, L2 to ground = 110V. L1 to L2 = 220 V.
With the three phase, L1 to L2 = 220V, L1 to L3 = 220V, and L2 to L3 =220V, but can vary depending the delta or yagi (Y) configuration provided by the power company. Where I live, we also have one leg that is higher than the other to ground, the stinger phase or wild leg. Gets pretty crazy!!!!
I apologize if I have confused you even further.
Steve