Generator Transfer Switch Outside

Hello Folks,
I finally got around to figure out the spot for a new transfer switch which I acquired some time ago. It is a small 5000 watts transfer switch (comes with relatives short wires), and it needs to be installed outside, and the only location outside would be on the same wall (exterior siding) whereon the circuit breaker panel hangs inside (interior of the premises). But then this wall (shown in the pic) is narrow and is sort of cramped and crammed with wires and stuff (socket meter nearby, conduits going up and down). The transfer switch in this case is a metal box hanging up on the wood sidings (the circuit breaker panel is right behind it. But I am not sure if this spot is ok, and what would be the requirement of clearances if any.

I think this has been missed so I thought I would bump it up.

Well, I guess I will answer my original aging question with some repetition... I did some reading and discussed this question elsewhere

I finally got around to figure out the spot for a new transfer switch which I acquired some time ago, there aren't many choices in terms of spots since the transfer switch needs to be close to the breaker box. It is a small 5000 watts transfer switch (comes with relatives short wires), and it needs to be installed outside, and the only location outside would be on the same wall (exterior siding) whereon the circuit breaker panel hangs inside (interior of the premises). But then this wall (shown in the pic) is narrow and is sort of cramped and crammed with wires and stuff (socket meter nearby, conduits going up and down).






The area marked with an 'X' indicates the non-drilling area (breaker box present on the other side). The areas marked with a rectangle shows area passive to be drilled in order for conduit and wire to travel to the other side (interior) and enter the circuit breaker panel.

Previously (first pic) the access to the transfer switch was not complying with code due to having the socket meter partially obstructing its access clearance. I then moved the transfer switch box further to the right (complying with the clearance requirements), and used ¾ PVC conduit which then travel sideways few inches from the transfer switch box towards the left and enters the inside of the room by means of a close 90 deg elbow through a bored hole in the siding. Inside the conduit protruding from the bored hole has yet another close 90 elbow which will then with a small section of conduit enter the breaker panel using a hole drilled on the side of the panel due to lack of knockouts on this part of the panel. The pics below depict the inside and outside scenarios:







The pic of the outside also shows a ¾ underground pvc conduit along with wires coming from garage subpanel. Originally the pvc conduit protruding from the ground is ¾, but in order to make it easy to fish the large caliber aluminum wires from the ground conduit to the circuit breaker panel inside I decided to transition to 1" pvc conduit.

I can't help with your question, but I have one of my own.

Un-fused cable between meter and breaker box.

Only from what I have seen here.
An armor cable between the meter and the breaker in a wall cavity up to 36". If it is more than 36" we have filled the cavity with concrete or they add a fuse box and just lately I saw a meter box with a main breaker built in.

So I forgot to ask the question. if you had a meter box like this could you do you transfer there?

nealtw said:

So I forgot to ask the question. if you had a meter box like this could you do you transfer there?

Click to expand...

I never saw this type of socket meter box with a means of disconnect built-in. It is very neat. At very least it would allow for easily replace a circuit breaker panel very safely without unhooking the power from the pole. I understand that a transfer switch is more sophisticated type of 3-way switch that would not allow one to back feed power to the utility company. :hide:

If the breaker switches built-in into the socket meter are transfer switches types and it does not have an exterior grade power outlet and nema receptacle built-in as well, I imagine that you would need to add an exterior grade power outlet like the one shown below.



The one below is a whole kit without a built-in receptacle in the transfer switch itself:


Some power companies provide a socket meter with a built-in outlet for a portable generator as the one below:

http://www.crpud.net/stay-safe/outage-center/generlink-transfer-switches

That's way beyond what I can comment on.

We do a lot of telco work . In all of those installations ( much larger than your situation ) , the electrical service feeds a main circuit breaker .

The main circuit breaker feeds the " normal " side of the transfer switch .

The generator has its own main circuit breaker . That feeds the " emergency " side of the transfer switch .

The 3rd side of the transfer switch , " load " , feeds the building service panel .

You probably do not wish to pay the price of a transfer switch , of ampacity equal to your electrical service ( 200 amps ? ) .

For a home , it may be easier to install a sub-panel , to serve the critical loads . I would size it to the max amps your generator can supply & feed it , on the " normal " side with a circuit breaker and wire of the same amperage .

I would run generator power to the sub-panel & use an interlock kit yo prevent the sub-panel from being energized by both sources at the same time . You may or may not be able to also use such a kit on your service panel / loadcenter ?

https://www.google.com/search?q=sq+d+interlock+kit&ie=utf-8&oe=utf-8

God bless
Wyr

WyrTwister said:

We do a lot of telco work . In all of those installations ( much larger than your situation ) , the electrical service feeds a main circuit breaker .

The main circuit breaker feeds the " normal " side of the transfer switch .

The generator has its own main circuit breaker . That feeds the " emergency " side of the transfer switch .

The 3rd side of the transfer switch , " load " , feeds the building service panel .

You probably do not wish to pay the price of a transfer switch , of ampacity equal to your electrical service ( 200 amps ? ) .

For a home , it may be easier to install a sub-panel , to serve the critical loads . I would size it to the max amps your generator can supply & feed it , on the " normal " side with a circuit breaker and wire of the same amperage .

I would run generator power to the sub-panel & use an interlock kit yo prevent the sub-panel from being energized by both sources at the same time . You may or may not be able to also use such a kit on your service panel / loadcenter ?

https://www.google.com/search?q=sq+d+interlock+kit&ie=utf-8&oe=utf-8

God bless
Wyr

Click to expand...

The interlocking kit is a much cheaper and simpler solution, but I would rather use a transfer switch. The one I am using is a small 5000 watts transfer switch, and it can not be connected to the main breaker: it can only be connected to two branch circuits (each being 120V and 20amps) or to a single 220V dual pole breaker (40amps). This transfer switch has two 3-way switches and it would not be possible to energize the panel by both sources at the same time (assuming its is properly installed). Also, it should be connected to a portable generator only which does not require a switch in between.

Indeed, most any small generator has a small circuit breaker is switch besides the on/off switch.

Yep, it is 200amps panel. But I don't plan on powering all the branch circuits, just two essential ones (2 20 amps branch circuits) in case of emergency.

The following is a link to transfer switch I am using:

http://www.amazon.com/dp/B00AHTWNH2/?tag=skimlinks_replacement-20

I never cogitated using a sub-panel in this situation, not show how it would work out.

Thanks for you input!

tk3000 said:

The interlocking kit is a much cheaper and simpler solution, but I would rather use a transfer switch. The one I am using is a small 5000 watts transfer switch, and it can not be connected to the main breaker: it can only be connected to two branch circuits (each being 120V and 20amps) or to a single 220V dual pole breaker (40amps). This transfer switch has two 3-way switches and it would not be possible to energize the panel by both sources at the same time (assuming its is properly installed). Also, it should be connected to a portable generator only which does not require a switch in between.

Indeed, most any small generator has a small circuit breaker is switch besides the on/off switch.

Yep, it is 200amps panel. But I don't plan on powering all the branch circuits, just two essential ones (2 20 amps branch circuits) in case of emergency.

The following is a link to transfer switch I am using:

http://www.amazon.com/dp/B00AHTWNH2/?tag=skimlinks_replacement-20

I never cogitated using a sub-panel in this situation, not show how it would work out.

Thanks for you input!

Click to expand...

If you wish more information on a sub panel , feel free to contact me via email .

God bless
Wyr