New sub panel

[taterdog]

Im moving into a new house that has an old fuse style sub panel in the detached garage. its fed from a 100 amp breaker on the house panel (which is a breaker style panel) im wanting to upgrade and install a new panel into the garage that uses breakers. Im confident in my abilities to do it on my own although im not entirely sure what kind of panel i should buy, from where (besides the obvious lowes/HD), an approximate cost, and if im "legally" allowed to. The panel has 240v and is grounded VIA a rod in the ground. (if this info helps any)

Thanks for the info in advance

 

[PRH44]

A few things to note before you get started. This information is needed to recommend any further work
1. Confirm the wire size and type insulation feeding that panel, It should be printed on the wire. Confirm copper or aluminum
It doesn't look like # 2 or larger.
2. Confirm the number of conductors leaving the house main panel and feeding your sub panel. It looks like you have 3 wires two hot legs and a neutral.
3. Confirm the ground wire is connected to the ground rod only and does not run back to the house panel.

 

[taterdog]

it was my grandfathers house, ive seen the rod buried outside the shop, eyeballin looks like 4ga, i can see 3 connectors coming in (i know its got 240v because i wired the window AC unit in, and its got a 240 plug for the table saw), and i havent looked at what kind of wire yet. I do know the house and shop were built in about 84-86 i cant remember.

 

[PRH44]

I need to know wire size and insulation so I can determine the 100 breaker will work. If it is in fact # 4 you will be in the 70 amp range depending on the insulation.
You need 4 conductors from the house panel to the sub panel if you plan to upgrade, and be code compliant.
At the time the panel was installed a 3 wire system was acceptable.

 

[pattenp]

Another thing is the individual wires that are providing the service to the sub need to be in conduit inside the building to the panel. How are they run from the house to the garage, direct buried or in conduit?

Subject to everything being ok I suggest a 20 space 100A main breaker panel for the sub.

Look through this thread for some info: http://www.garagejournal.com/forum/showthread.php?t=138974

 

[taterdog]

i dont know if there run through conduit to the shop. what is the 4th wire? the ground? my issue is i have asphalt in the way of making a new run to the shop. we have an inspection coming from the bank soon to assess the value before we close. Is there any chance the inspector will require us to do a 4th wire upgrade before they will close?

 

[pattenp]

The bank appraiser is not going to be too concerned with that. They aren't doing a safety/electrical code inspection.

The four wires will be two hots, one neutral and one ground. Once upon a time the equipment ground back to the main was not required, but how many years ago that was I don't know.

 

[taterdog]

The bank appraiser is not going to be too concerned with that. They aren't doing a safety/electrical code inspection.

kind of what my assumption was. What will happen if i was to install a new breaker style sub panel without making this 4th wire addition.

 

[pattenp]

Where/how do the service wires enter the garage or leave the house?

 

[pattenp]

It just won't be to current code. You also need to add a second ground rod if there is only one.

kind of what my assumption was. What will happen if i was to install a new breaker style sub panel without making this 4th wire addition.

 

[taterdog]

It just won't be to current code. You also need to add a second ground rod if there is only one.

i could be incorrect in thinking there is only 1. What is the disadvantage of leaving the 3 wire setup in place and not going to a 4 wire? i do understand the advantages of a good ground which is why i wouldnt question a 2nd grounding rod. Any suggestions on a panel to use?

 

[taterdog]

Where/how do the service wires enter the garage or leave the house?

I honestly have no idea how they enter/exit i really want to say that there is no conduit that i can see. i just havent paid that much attention to it.

 

[pattenp]

I don't know the technical reason why code was changed requiring a four wire feed from a three wire feed.

As I said before I suggest a 100A 20 space main breaker panel. The Square-D is one that comes to mind and is carried at Lowes.

i could be incorrect in thinking there is only 1. What is the disadvantage of leaving the 3 wire setup in place and not going to a 4 wire? i do understand the advantages of a good ground which is why i wouldnt question a 2nd grounding rod. Any suggestions on a panel to use?

 

[taterdog]

I don't know the technical reason why code was changed requiring a four wire feed from a three wire feed.

As I said before I suggest a 100A 20 space main breaker panel. The Square-D is one that comes to mind and is carried at Lowes.

thanks for the info. i do have just 1 more question

http://www.lowes.com/pd_71846-296-Q...e+line&page=3&Ns=p_product_price|1&facetInfo=

http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

why is the 24 circuit panel cheaper and it even comes with breakers?

 

[Norcal]

thanks for the info. i do have just 1 more question

http://www.lowes.com/pd_71846-296-Q...e+line&page=3&Ns=p_product_price|1&facetInfo=

http://www.lowes.com/ProductDisplay...gId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

why is the 24 circuit panel cheaper and it even comes with breakers?

One is a QO, & the cheaper one is a Homoline. If it was my choice I would choose the QO loadcenter, copper bus & Visitrip feature on the breakers, even though it's more expensive.

 

[taterdog]

One is a QO, & the cheaper one is a Homoline. If it was my choice I would choose the QO loadcenter, copper bus & Visitrip feature on the breakers, even though it's more expensive.

so i should go with the 20/20 100a for $97

 

[pattenp]

Both of them will work fine. Spend what your wallet can stand. The 24 space one is a better deal with the breakers and I don't have a problem using the Homeline, got one in my detached garage. Another one to look at is the Cutler-Hammer CH brand, Lowes sells that too. http://www.lowes.com/pd_101589-8236...entURL=/pl__0__s?Ntt=cutler+hammer&facetInfo=

 

[pattenp]

The Cutler Hammer CH series is the higher quality panel vs. the Cutler Hammer BR series. Same goes for the higher quality Square-D QO vs. the Square-D Homeline.