OT Power Sag Correction vs. Arc Flash

Hello all. I haven't visted in a bit, but am back with an off topic question for those of you with an OSHA and power management type background. We are presently looking for options in our energy management which will help with poor electrical signal condition.(surges, sags, etc.) We've had issues with things like T-storms affecting equipment as long as I've been here. We are looking at purchasing a DySC(Dynamic Sag Corrector) for strategic locations to help with the issue. The problem I have is that these systems are designed to sense issues with the signal, then transfer energy from one leg to another for up to 12 cycles. I'm wondering what effect this has on equipment arc fault ratings which sit downstream of these DySC's. Has anyone had any experience with them as far as this is concerned? This is a new venture for me, and I'm very much interested in learning about a totally new topic. Thanks in advance.

Russ

Equipment does not have arc fault ratings.

Equipment has bolted fault short circuit current ratings, AIC (interupting rating) for protective devices like breakers and SCCR (or withstand) ratings for panels, conductors, and non-fused switches.

The arc flash hazard risk category is determined for an equipment location based on the available fault current at the location and the clearing time of the upstream protective device.

Jim Dungar said:

The arc flash hazard risk category is determined for an equipment location based on the available fault current at the location and the clearing time of the upstream protective device.

Click to expand...

Jim,

I understand that equipment does not have an arc flash rating. My question involves more of what you stated, the clearing time of the upstream protective device. We are considering installing a device which will read sags on one leg and rob energy from the remaining legs in order to fill the sag on the problem leg. I'm wondering if anyone has any experience with these devices and I'm wondering if this device would have any effect on the arc flash rating of the downstream environment. I didn't phrase this correctly the first time. Suppose I have a panel with a rating of 2. If I install this type of device upstream on the lines feeding that panel, I am wondering if the device would have any effect on the protective device seeing the fault condition. For instance, I have a short on one leg, this DySC tries to correct the problem for 12 cycles. Would this delay my protective device's respone by 12 cycles as well, and in turn alter my AFI rating?

I am not familiar with the method you are using to supply power to the sagging legs. However, it sounds like your device will act like a source which will feed additional current into the fault. I would expect this to increase the arc flash incident energy by increasing the current at the fault point, similar to the effect a large motor has on faults.