Outbuilding wire

[MarkB_MI]

I'll tell you what I used for my shop, which is about 100 feet from my house. I used a 100 amp panel and ran four conductors of AWG 2 USE-2. This has worked out well. The biggest load I have is my welder, which requires a 50 amp circuit. The inspector was picky about the grounding at the shop: Two ground rods eight feet apart, plus the two yard hydrants (one inside and one outside) had to be bonded to the ground wire as well.

 

[MarkB_MI]

> Just 60A he is easing in on retiring and just wants to pluck around on a few things

Go with 100 amps. I don't think there are any 60 amp panels that have an adequate number of slots for even a small shop. And aluminum AWG 2 USE-2 wire is cheap, so it probably won't cost much more than the AWG 6 copper cable you would use for 60 amps.

 

[MarkB_MI]

> Interesting you are saying 4 conductors. I'm guessing that's a code requirement. 27 years ago when I ran an entry cable to my mobile home the instructions said 4 wire as well but I couldn't find it. I finally went to one supplier who after I told him the situation said I'm going to give what you need. It was 3 wire. 2 hots and a neutral. It was UF wire and I buried it directly in the ground. #2(?) aluminum cable I believe. I tied the neutral bus and the ground bus together inside the house panel just like I see in regular houses and factory panels that have no separate ground bus and grounded the neutral/ground bus with an 8' copper rod underneath the house. I've had no problems. If I had found 4 wire they would have been connected together in the 100 amp disconnect breaker box at the pole anyway. Not code?

Current code is to run separate ground and neutral from the main disconnect to an outbuilding. The ground conductor needs to be grounded at the outbuilding as well. The old code allowed only three conductors at the oubuilding, but still required a separate ground rod at the outbuilding and required ground and neutral to be kept separate at the outbuilding.

As for mobile homes, I'm pretty sure the code has required four conductors for more than 27 years.

 

[Hemmjo]

How are you measuring that voltage? Where are the meter probes? Measure; Hot to Neutral, Hot to Ground, and Neutral to Ground. What are those readings.

One possibility is a leaking switch. Moisture could have invaded the switch allowing a tiny amount of current to pass when the contacts are open.

Lots of other possibilities for a voltage leak.

 

[MarkB_MI]

> How about explaining 20 volt from panel to bathroom with nothing turned on???

Noise.

 

[Hemmjo]

Forgot to mention. Depending on how the hose was wired, there can be many connections between the panel and where you are measuring the voltage. Anyone, or more than one, of those may have a bad connection creating resistance and low voltage.

Many homes are wires using back stab devices, where the wire is stripped then just shoved into the back of the device. The connection is made with a very small, very thin strip that digs into the conductor. These connections fail over time. I have lost count of how many I have replaced over the years.

The NEC should be ashamed of itself for ever allowing them in the first place.

 

[John T]

Good morning again Nate, as I posted below BEFORE you can size the wire you FIRST have to decide how many Amps of current you will supply to the outbuilding ??

NEXT you have to decide if you want to direct bury multiconductor cable such as UF or USE etc. etc. ORRRRRRRRRRR to use buried conduit with individual conductors such as copper wire type THWN??

NEXT use Aluminum or Copper conductors ??

NEXT compute Line Voltage Drop and if excessive upsize cables

FINALLY consult ampacity charts for the conductors you have chosen TO GET YOUR ANSWER OF WHAT SIZE CABLE IS REQUIRED

NOTE As different types of cable,,,,,, different methods such as direct bury or enclosed in conduit,,,,,,,,different distances,,,,,,,,copper or aluminum conductors,,,,,,,all make a difference, the size you need may or may NOT be the same as someone else used. Of course what someone here used if given the same service requirements ???? might be the same as what you need !!!!!! Your choice take your pick

If you google wire ampacity charts you will get hundreds of hits and below is ONLY ONE SEARCH START so just be aware to consider all the above so you use the correct chart.. I would err on using too large cable versus too small cable myself to allow for upgrades PLUS reduce line voltage drop and while a 60 Amp service may well get you by, Id consider running a 100 Amp service to allow for upgrades.

Compute current requirements, decide on service size, compute distance, compute line voltage drop, decide what type of cable, direct burial or conduit, CONSULT AMPACITY CHARTS that match your chosen cable and method, install a SUB PANEL with separate insulated and isolated Neutral and Ground Buss, provide proper Grounding at sub

Sorry I cant spoon feed you any easy answer not knowing current, distance, type of cable and method selected and wire etc. etc. etc. Where fire and life safety are concerned (do NOT take my word for it) you might want to at least consider consulting the NEC, professional electricians or engineers, or any applicable local authority in addition to the advice offered here (me included)

John T Best wishes be safe
Cable Ampacity Charts

 

[olddavid]

As for mobile homes, I'm pretty sure the code has required four conductors for more than 27 years.

Thanks for your comments and yes, four wire was specified in the manual but like I said I couldn't find it. I wired it in accordance with '93 codes for a regular house entrance cable which required the neutral and ground to be tied together and bound to the service panel with an external earth ground coming off of that. Times do change.

 

[John T]

You posted: a regular house entrance cable which required the neutral and ground to
be tied together and bound to the service panel with an external earth ground coming
off of that. Times do change.

I don't think its changed as far as how a homes main service entrance panel is
configured VERSUS a sub panel.. From the homes transformer ONLY three wires are
required L1 L2 Neutral to the homes main service panel where theres a Neutral Ground
BOND thats also connected to all readily available Grounding Electrodes. After that
if you feed a Sub Panel 120/240 its THEN that 4 wires are required.

Thats how it was way back when I practiced, I dont think its since changed ??

Nice sparky chatting with you best wishes

John T

 

[John T]

I HATE and NEVER specified back stab receptacles grrrrrrrrrrr when I practiced nor ever since...Unfortunately I even see RV's that use them grrrrrrrr

John T

 

[Destroked 450]

In a small shop we re you will have a welder and air compressor you will possibly have a 60 amp panel loaded beyond it s rated capacity before adding anything else
As a retirement shop he may want a small heat source or window ac unit for a better work environment
These will put the demand well over 60 amp wire feeding the panel

We just run a 100 amp service 125 ft to my brothers small shop so he will have enough capacity to run his welder and air compressor plus extras

I live in a modular home and have recently added a two car garage. For the garage I ran a 60 amp service from the main panel to a 60 amp sub panel in the garage to power lights, outlets and one 30 amp 220 outlet should I install a air compressor or want to power a small mug welder

For your friends shop I go with 100 amp minimum

 

[waugh621]

Thank you for your help John i think i am sey on the right path and will probably have dad talk to a local pro about how to burry for ou area
Nate

 

[John T]

You're welcome, Id sure consider a 100 Amp Sub Panel configuration and service and be done with it which allows for expansion. Direct bury multi conductor jacketed cable is one easy not too expensive route and aluminum wire works fine provided you use the anti oxidant and proper torque EASY PEASEY......

John T

 

[John T]

When I was practicing electrical power distribution in accordance with then NEC
standards as far back as the 80's MOBILE HOMES WERE FED WITH FOUR WIRES (for
120/240) as the pole disconnect and breaker was considered the MAIN while the mobile
homes panel was then treated as a SUB PANEL.

HOWEVER a homes main panel is as I posted above:

I don't think its changed as far as how a homes main service entrance panel is
configured VERSUS a sub panel.. From the homes transformer ONLY three wires are
required L1 L2 Neutral to the homes main service panel where theres a Neutral Ground
BOND thats also connected to all readily available Grounding Electrodes. After that
if you feed a Sub Panel 120/240 its THEN that 4 wires are required.

Thats how it was way back when I practiced per NEC standards, I dont think its since
changed ??

Nice sparky chatting with you best wishes

John T Long retired power distribution engineer SO NO WARRANTY consult the NEC

 

[buickanddeere]

Not saving any money going with 60 instead of 100.
Eventually he will have a fridge , microwave , heat, electric car charger and air conditioning out there .

This post was edited by buickanddeere on 10/10/2023 at 03:12 am.