Fifth Jaw Meter Socket

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johnuia

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Can someone give me a layman's understanding of the reason for and useage of a fifth jaw meter socket? While I'm at it, is the meter bypass used simply to bypass the meter completely and draw power from the service with the meter removed?
 
Re: Fifth Jaw Meter Socket

A 5 jaw meter gives uou a place for a neutral, which will allow for more accurate measurement of unbalanced single phase loads.
The meter bypass allows you to remove the meter without interrupting power to the customer, also to remove the meter safely if the utility can't find the service disconnect.
Jim T
 
Re: Fifth Jaw Meter Socket

I'll through in my 2 cents but jtester's answer is fine also.


fifth jaws are installed on single phase systems where supplied by a three phase network. 120/208V in most cases. The poco buys watthour meters with a split potential coil. 120V + 120V. The meter takes 240V to accurately indicate the amount of energy consumed. Even if only one phase is loaded. They give nothing away!

If the meter sees 208 accross the the two 120V coils in series it will read less power consumed.By addeding the fifth jaw and bringing the neutral to the center of the two coils the meter thinks it is looking at 240V.

Charlie
 
Re: Fifth Jaw Meter Socket

Meters are a subject I'm not that familiar with either.

Correct me if I am wrong: a 4 jaw would have 2 lines in, and 2 lines out. The 5th jaw would land both the neutral in and out?

Then a 3 phase would have 7 jaws with 3 lines in and 3 lines out and a 7th jaw for the neutral in and neutral out?

If we bond the neutral and ground in the meter enclosure, does the ground and bonding jumper also land on the 5th or 7th jaw?

Finally, what is the difference between a lever bypass and a horn bypass?

Thanks:
Steve
 
Re: Fifth Jaw Meter Socket

You would not bond in the meter you would bond the neutral in the fist mean of disconnect.
 
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