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Electrical panel emergency disconnect, ground rods and sound quality

I finally pulled the trigger on upgrading my house old electrical panel (load center) setup that wasn’t properly grounded.

I went with the Square D QO series panel, whole house surge protection and 2x8' ground rods and 4ga solid copper ground cable per NEC code. My electrician drove ground rods at a 7' distance between them per code. I learned too late that there is a recommendation for optimal distance between ground rods to be about 2x the length of the rods. Oh well...

Even so, I could clearly hear improvement in my system and it was not subjective. I no longer hear a transformer-like buzzing noise coming from my speakers that would increase with volume. Instead I hear a much softer noise similar to an AM radio being tuned. I have to be right next to tweeter and volume up pretty high to hear it. I’m sure that noise was always there but masked our before the upgrade.

City inspector, however, faulted new panel install for the lack of an outside emergency disconnect between it and the meter per NEC 230.85. My electrician thinks it’s completely unnecessary and that requirement will be done away with in the next NEC revision, but I digress.

Is there an opinion about which brand/type of emergency disconnect has the least negative effect on the quality of power coming into the house?

How much my ground effectiveness has been reduced by having distance between ground rods be less than 2x their length?

All in all, I highly recommend this type of upgrade for older electrical systems!

dmk_hifi

Showing 2 responses by jea48

jea48
4,303 posts
 

@dmk_hifi

Plain and simple your electrician didn’t look at the code changes for NEC 2020 edition from the previous 2017 edition.

The Emergency Disconnect is for the fireman’s safety when entering a house if there is a fire.

As for there still being live power at the meter that is not a safety issue for the fireman. If the fire has burned over and or around the meter socket the Utility Power Co is called and the power is disconnected from the dwelling unit.

Power Companies do not allow a disconnect ahead of the meter socket for a residential dwelling unit. Sequence is meter >> Switch >> Fuse.

As for securing the EM disconnect on the outside of the house there is a provision on the enclosure for installing a Padlock that secures the outer metal cover. The Fireman has a master key for all Padlocks made... It called a bolt cutter.

The AHJ (Authority Having Jurisdiction) has the final say. If the electrician is arguing with the inspector he is only digging the hole deeper. I hope you got a contract price from the electrician for doing the job...

jea48
4,303 posts
 
dmk_hifi OP
46 posts

Good stuff. Sounds like brand/type of disconnect doesn’t really matter provided it has the right amp rating.

@dmk_hifi

WRONG!

Your electrician better read 2020 NEC 230.85 very carefully...

"For one- and two-family dwelling units, all service conductors shall terminate in disconnecting means having a short-circuit current rating equal to or greater than the available fault current, installed in a readily accessible outdoor location. "

I doubt any non fuseable 2 pole safety disconnect switch will meet this requirement. A 22kA breaker would though. (22,000 Amps). Like I said earlier it shall be rated and Listed for use as service equipment...

Also I imagine your electrician will use 230.85 (3) wiring scheme and Label the disconnecting means,

(3) Other listed disconnect switches or circuit breakers on the supply side of each service disconnect that are suitable for use as service equipment and marked as follows: “EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT”

EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT

 

I would strongly suggest the electrician check with the Utility Power Co, Electrical Inspector, Electrical Wholesale Supply House for what meets the requirement for your area before he buys anything.

Jim

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