Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Do you experience less voltage drop with a cable like SER or MC then you would with a rigid pipe with wires?
VD
- Thread starter Alwayslearningelec
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ptonsparky
Tom
- Occupation
- EC - retired
Good theoretical question. Normal day to day operations or under bolted fault conditions?
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I thought maybe this was going to be a medical question.
ptonsparky
Tom
- Occupation
- EC - retired
Fortunately, I have little experience with either. Make that none.
ptonsparky
Tom
- Occupation
- EC - retired
Rigid what?
wwhitney
Senior Member
- Location
- Berkeley, CA
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- Retired
See the "Effective Z" columns in Chapter 9, Table 9, for an example of the effect. I assume a cable with a non-metallic sheath (e.g. SER) would be akin to PVC conduit, while aluminum MC would be akin to aluminum conduit, and steel MC would be akin to steel conduit.
Cheers, Wayne
drktmplr12
Senior Member
- Location
- South Florida
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- Electrical Engineer
theoretically, it comes down to a question of how the cable and conduit/MC sheathing geometry affects the reactance. I would expect capacitive reactance to increase as the distance from sheathing to conductors decreases like a tube capacitor. to what degree, i defer to those much smarter than myself.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
I'm coming up with different sizes on diff calculators. Can someone check.
480v
800A load at end
600'- run in mc cable
CU = 4 sets #250
AL = 4 sets #400
480v
800A load at end
600'- run in mc cable
CU = 4 sets #250
AL = 4 sets #400
Unsure what you are looking for but.....
Using Mike's free calculator those 2 runs are comparable with both giving you about 10 volts drop
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