Electrical problems at home related to RPC

This is one of the reasons I am so PRO about VFDs. They allow you to soft-start the machine motor, they don't draw huge reactive or startup currents, and you get variable speed and machine motor braking, too. Nobody in the house knows when my machines are running, because there is no electrical disturbance.

Jon

Not exactly, All three of my VFD's will wipe out AM radio reception on a line powered radio. Battery powered radios are OK until I get within about

Randy

AM? *blink*

Pete C.

Sounds like you have an excuse to upgrade your electrical service. The problem isn't your RPC, that's a perfectly normal home shop item, the problem is your inadequate electrical service.

Tell the SO that your glad the RPC has pointed out the potentially dangerous deficiencies of the homes electrical service so you can upgrade to 400A service before there is a fire or something.

Pete C.

Well, actually, that isn't so ridiculous. My dad remarried about 15 years ago, and they were having problems in her house, with lights going out and then coming back on later. I said that sounded serious, call your electrician. The licensed. professional electrician said it was "normal, nothing you could do"! I said, "wow, you need a new electrician!" My dad didn't want to believe me, then his next-door neighbor, who is an EE, agreed, in much stronger terms. Well, nothing happened until I got a chance to visit. I pulled the cover off the electrical panel, and many of the wires were so loose in the breakers you could just pull them striaght OUT! Yikes! So, I retorqued all the hold-down screws, and there were no further problems. EVERY screw in the panel was loose.

If Igor has a reasonably-rated electrical service, this could be the same problem. Anyway, that is something he can check. And, if he has anything less than a 100 A service, he really is not going to be able to run a 10 Hp idler motor. With typical house loads running, you really don't want any less than a 200 A service to run this kind of equipment.

Jon

Large rotary converters will draw large currents during startup unless spun to speed first. Consider a pony motor.

Also be sure your neutral at the panelboard isn't getting loose. Strange things can happen if this occurs.

Jim

...

Thanks Mike, that's a good point and one I may have to consider.

In my experience, the worst power spikes you can get are when you start to spin the motor up, but before it gets to speed you disconnect power. Especially if you've got a wimpy power switch, it'll arc over and you get a big dump into your house's power.

Out of curiosity, what do you use to switch 120 Amps?

Tim.

Do you spin the smaller idler up first? If not it would likely help start the larger one.

Pete C.

Thanks Jim, I will think in that direction if I cannot do anything else.

My motor is 240v, but yes, loose connections could account for it. I feel that it is unlikely to be an issue, but I will check that in any case.

Good points...

I use a Allen Bradley "Nema Size 2 Motor Starter".

I spin up the larger one first, as of now, because it takes less capacitance to spin up. I will definitely consider your point.

Thanks. I will check all set screws in all panels.

It is a 200A service.

Thanks for some food for thought. I will check all electrical set screws.

Don't overlook the incoming power feed. Those crimp connections the power company uses ar pretty good but they do fail over the years. I have had several problems very much like Iggy's and they were corrected by the power company fixing their lines. You can usually see signs of a problem on the connections insulation. One place you could see blue arcing at night when the electric furnace kicked in! Wind storms would turn the TV on and off and fried a microwave oven.

And just for the record, I have enjoyed your trials and tribulations with your various projects. Keep us posted please :)

Glenn

Yes, I will definitely check that. My incoming power lines are connected to the electrical panel with Allen style set screws. They are before the main breaker, so, I will have to be very careful tightening them, as they cannot be turned off.

The electrical lines coming into the house are underground.

Thank you. Same to you.

Iggy, I hate to bring this up, but what ever happened to your mysterious motorcycle engine? Bill.