Furman Power Conditioner Issue?

K

Kip Conner

Junior
Mar 13, 2011
370
0
0
Athens, GA
Here's a new one, for me.

I don't use a lot of power conditioning in my system, only where there is rack gear or consoles. Amps go straight into the wall power.

Last saturday I was doing an outdoor show on a golf course driving range that was closed to all vehicle traffic. A member went out of his way to drive his cart down to see what we were doing and drove over my snake and power cables going to FOH before we could put down any cover. While the weight of the cart wasn't enough to damage the two whirlwind snakes or the heavy SJO cable, there was another power cable that was running to FOH that had the console on it and rack on it. He spun the tires and created a small tear in the jacket of this power cable tripping the breaker on the spider box.

We pulled a new power and the breaker kept tripping. We went direct to the gear around the furman and the breaker stopped tripping. It took several quad boxes to get all the power we needed back at FOH. Today I pulled the rack out and the Furman appears to be working fine. I plugged a fan into it to put it under load and it's not tripping the 20A wall circuit.

Thoughts?
 
Re: Furman Power Conditioner Issue?

I talked to the guys at Furman and they think the relays just needed time to reset themselves. Not buying per se, but everything seems to work fine now.
 
Re: Furman Power Conditioner Issue?

I checked all the cabling today and even re-applied new heat shrink to the connectors where I cut off the 10' cable to make it short for a rack.

The tech I spoke to thinks that one of the 60cycles experienced upwards to a 180v spike when it got runneth over.
 
Re: Furman Power Conditioner Issue?

Alan Sledzieski said:
I don't see how it would get a 180v spike.
Click to expand...

Neither do I. Voltage isn't going to mysteriously appear, unless there was another leg involved. The Furman is only designed to handle issues on the load side, perhaps if there was an issue on the line side like a hot-neutral or hot-ground jump, it would freak out?

Kip Conner said:
the heavy SJO cable
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Kip, according to the NEC, anything with a "J" in it isn't allowed where there is public access. Perhaps you now know why the code reads the way it does; SO cord would likely have survived fine.
 
Re: Furman Power Conditioner Issue?

Alan Sledzieski said:
I don't see how it would get a 180v spike.
Click to expand...

Silas Pradetto said:
Neither do I. Voltage isn't going to mysteriously appear, unless there was another leg involved. The Furman is only designed to handle issues on the load side, perhaps if there was an issue on the line side like a hot-neutral or hot-ground jump, it would freak out?
Click to expand...

It's possible to get high voltage spikes if there's any inductance involved and the current is interrupted (that's what causes the arcing when you unplug certain loads hot). Now, a single spike of that magnitude shouldn't have damaged the MOVs that the Furman unit uses for protection, but that's a different discussion.

The other possibility is that the breaker was a GFCI breaker, and you've got a short or significant leakage current from line to ground (either in the wiring or from a damaged MOV).
 
Re: Furman Power Conditioner Issue?

Rob Timmerman said:
It's possible to get high voltage spikes if there's any inductance involved and the current is interrupted (that's what causes the arcing when you unplug certain loads hot). Now, a single spike of that magnitude shouldn't have damaged the MOVs that the Furman unit uses for protection, but that's a different discussion.

The other possibility is that the breaker was a GFCI breaker, and you've got a short or significant leakage current from line to ground (either in the wiring or from a damaged MOV).
Click to expand...

He didn't identify which Furman he has; the new ones don't use MOVs.
 
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