Voltage Drop

[rheydel1]

What is the maximum voltage allowed on a motor circuit and where do I find this in the N.E.C.

 

[rheydel1]

Voltage Drop

I meant the maximum allowable voltage drop allowed on a motor circuit and where do I find that in the N.E.C.

 

[iMuse97]

See 210.19(A) FPN No. 4 (where FPN stands for fine print note). As many on this forum will tell you, the fine print is not enforceable code, but with motor applications you don't need excessive voltage drop, but then you know that being in a plant.:grin:

 

[drbond24]

The NEC only provides recommendations for maximum voltage drop, not requirements. If you are wanting to know the lowest voltage at which the motor will still operate properly, I'd ask the manufacturer.

 

[bphgravity]

Also check your local energy energy efficiency code for voltage drop regulations...

 

[weressl]

Drop, drop, drop....the age old question!

Drop, drop, drop....the age old question!

What is the maximum voltage allowed on a motor circuit and where do I find this in the N.E.C.

IEEE/ANSI Standard design allowances are 2% for distribution and 5% for branch circuits.

 

[mivey]

What is the maximum voltage allowed on a motor circuit and where do I find this in the N.E.C.

From ANSI C84.1:

Normal operation: 108 to 125 on a 120 volt basis. Should operate satisfactorly.

Infrequent operation: 104 to 127 on a 120 volt basis. Might operate at acceptable performance levels. Protective equipment might take motor off line.

Abnormal levels:<104 or >127. Protective equipment will probably take the motor off line.

 

[skeshesh]

VD

VD

The nec doesnt have requirements only recommendations as stated. For motor application I'd agree with drbond24 - you should get your hands on some data sheet or spec from the mfg. to see what the operating voltage is, then size to keep the drop in range of operating voltage.