8 Gauge Wire 200 amp disconnect

[mbrooke]

Is 8 gauge wire on a 200 amp OCPD an allowable exception? What wiring method can be employed, ie does the wire have to be in a trough?

 

[Hv&Lv]

Line side tap, or the fact this is a substation battery charger and doesn’t count.

I guess you would have a fit to find out S&C motor operators have slugs installed in them rather than fuses..

 

[jim dungar]

Line side tap, or the fact this is a substation battery charger and doesn’t count.

I guess you would have a fit to find out S&C motor operators have slugs installed in them rather than fuses..

Aren't these conductors protected at their source, the battery charger, at 50A, the 200 fuse is not part of their protection. Is this why you say they "don't count"?

 

[mbrooke]

Line side tap, or the fact this is a substation battery charger and doesn’t count.

I guess you would have a fit to find out S&C motor operators have slugs installed in them rather than fuses..

I can do that; I assume the batteries deliver the power, and exclude the charger.

Question- how do I find out the short circuit output of a battery bank?

 

[petersonra]

I can do that; I assume the batteries deliver the power, and exclude the charger.

Question- how do I find out the short circuit output of a battery bank?

Ask the battery people. Batteries can pump out a lot of current in a dead short situation but it is unlikely to be tens of thousands of amps.

P.S. - what makes you think you can run cord from the charger to the 200 A disconnect?

 

[Hv&Lv]

I can do that; I assume the batteries deliver the power, and exclude the charger.

Question- how do I find out the short circuit output of a battery bank?

What’s the amp hour of the bank?

 

[Hv&Lv]

Aren't these conductors protected at their source, the battery charger, at 50A, the 200 fuse is not part of their protection. Is this why you say they "don't count"?

90
.2(B)

Aren't these conductors protected at their source, the battery charger, at 50A, the 200 fuse is not part of their protection. Is this why you say they "don't count"?

that and 99.2(b)

 

[Hv&Lv]

Ask the battery people. Batteries can pump out a lot of current in a dead short situation but it is unlikely to be tens of thousands of amps.

P.S. - what makes you think you can run cord from the charger to the 200 A disconnect?

That’s the charger circuit and it’s the way substation battery charger systems are generally wired.
Either that or direct to battery bank bypassing the disconnect, with a separate disconnect in the charger.

 

[petersonra]

That’s the charger circuit and it’s the way substation battery charger systems are generally wired.
Either that or direct to battery bank bypassing the disconnect, with a separate disconnect in the charger.

He seems worried about meeting code as far as the tap goes so why wouldn't he worry about the proscriptions on using cord.

 

[Hv&Lv]

90.2(B)

that and 99.2(b)

Typo and not paying attention... 99.2(B) was a screwup

we generally run an 8 or 10 gauge duplex red/black for the charger circuit.

 

[mbrooke]

What’s the amp hour of the bank?

I have to ask for the specs on the individual batts as they are not in the bill of materials price list (yet), but here is what the plan drawing shows:

 

[Hv&Lv]

I have to ask for the specs on the individual batts as they are not in the bill of materials price list (yet), but here is what the plan drawing shows:

View attachment 2557207

Standard run of the mill drawing off the internet.

 

[Little Bill]

I can do that; I assume the batteries deliver the power, and exclude the charger.

Question- how do I find out the short circuit output of a battery bank?

Another question:
Why do you need to know?

 

[mbrooke]

Standard run of the mill drawing off the internet.

Link me the same off the net.

 

[mbrooke]

Another question:
Why do you need to know?

Fuse selection and if that tap is protected.

 

[jim dungar]

90
.2(B)

that and 99.2(b)

90.2 is only applicable if this installation is a 'utility. I have designed and commissioned station battery systems like this for customer substations subject to the NEC.

 

[mbrooke]

90.2 is only applicable if this installation is a 'utility. I have designed and commissioned station battery systems like this for customer substations subject to the NEC.

Correct. If the substation is customer owned, the NEC technically applies. But in any case it is still nice to know you have something that won't present excessive hazard to vital assets.