Generator external connection and conduit

[Greg1707]

I am looking at the literature for the Siemens Generators. I do not see any specs for the length of the external conduit that connects the machine to the external connection box. I need to keep the machine five feet from the house and am concerned about the length of this important piece of the equipment.
So, does anyone know the length?

 

[petersonra]

it needs to be long enough to reach. i do not think there is either a minimum or a maximum length.

 

[hbiss]

Why do you think it would matter and why do you feel it is such "an important piece of equipment"? Generators are often located a lot more than 5 feet from buildings for many reasons. Size your wire accordingly if necessary.

-Hal

 

[ceb58]

The whip is around 5 ft long. All it is is a Generac with a different name. They advertise 18" from the building as long as there are no openings in the building with in 5 ft.

 

[goldstar]

Is the generator privately labeled for Siemens ? Possibly by Generac ? Anyway, unless the 5' rule is a local ordinance most municipalities will accept the manufacturer's recommendations. Generac, as an example, will allow you to place the unit 18" from the house unless there is combustible material present (i.e wood siding, deck, etc.). Otherwise 5' from such material or windows. Not sure what the other brands allow. If it's a pre-fab system (like a Generac essential circuits system) the whip from the generator is 6' long. If you're doing a "whole house" system you'll have to fabricate your own whip(s). I've run them in PVC alongside the house then down to the top of the shrub bed. Install one or two 12" pieces of pressure treated 4" x 4" to secure the PVC and gas line to and then transition the PVC to flex before you enter the generator.

 

[6sunset6]

Generac has a firecode rating now at least for the 8k -10-14 that allows 18" from combustible material. Still need 60" overhead to soffit and the 5' rule for windows and ignition points.

 

[Greg1707]

Generac Package

Generac Package

Generac has a firecode rating now at least for the 8k -10-14 that allows 18" from combustible material. Still need 60" overhead to soffit and the 5' rule for windows and ignition points.

I should have been clearer in my post. My customer has ordered a 17kw generator with a 16 circuit transfer switch. The specs show a two foot conduit from panel to transfer switch and a 30 foot conduit from transfer switch to external connection box. It does not show the length of the pre wired conduit from external connection box to generator.

There are windows near the suitable sites, so we must keep the generator five feet away from side of house, therefore; my concern about the length of the conduit.

If the conduit is only six feet long and I place the generator five feet from house--it may not be a pretty sight.

 

[ceb58]

I should have been clearer in my post. My customer has ordered a 17kw generator with a 16 circuit transfer switch. The specs show a two foot conduit from panel to transfer switch and a 30 foot conduit from transfer switch to external connection box. It does not show the length of the pre wired conduit from external connection box to generator.

There are windows near the suitable sites, so we must keep the generator five feet away from side of house, therefore; my concern about the length of the conduit.

If the conduit is only six feet long and I place the generator five feet from house--it may not be a pretty sight.

How much of the 30 ft whip do you need inside?

 

[goldstar]

Here's the problem with these units. The 6' whip from the generator to the connection box comes pre-wired. Inside the connection box the power wires are terminated and the control wires have Molex connectors on them. On the transfer switch end the 30' greenfield whip contains the wires that are to be connected to the outdoor connection box. On the far end of the whip the power wires are ring-spaded and the control wires have the matching Molex connectors. The 2' whip that connects the transfer switch to the breaker panel is metallic seal-tight. In your case the breakers included are (5) s/p 15's, (5) s/p 20's, (1) 2-p 20, (1) 2-p 40 and (1) 2-p 50. This is a pre-packaged, pre-engineered system and was submitted to UL as designed. I don't mean to de-rail this thread but these questions wers brought up in my contractors association meeting this past week :

• Can these whips be modified in any way without voiding the UL listing ?
• Can the breakers be changed to accommodate the actual circuits needed ?
• If my connection from the transfer switch to the generator is only 10' away am I supposed to coil the extra 20' in the ceiling rafters of the basement ?

Personally speaking, I have modified these whips numerous times and have not been cited for a violation (that's not to say that I'm right). I can't figure out why they use a 2' metallic seal-tight whip for an inside connection. It's a real PITA to work with and if you have to cut it down to accommodate your installation you have to remove the wires anyway. I've changed this to greenfield and again have not been cited. And finally I've changed the circuit breakers to accommodate my customers needs. In many cases I've had no need for a 2-p 20, 2-p 40 or a 2-p 50 breaker. If changing them and the wiring in the whip are violations what would be the right thing to do ? Leave them unused in the sub-panel and safe-off the wiring on the main breaker side ?

 

[ceb58]

Here's the problem with these units. The 6' whip from the generator to the connection box comes pre-wired. Inside the connection box the power wires are terminated and the control wires have Molex connectors on them. On the transfer switch end the 30' greenfield whip contains the wires that are to be connected to the outdoor connection box. On the far end of the whip the power wires are ring-spaded and the control wires have the matching Molex connectors. The 2' whip that connects the transfer switch to the breaker panel is metallic seal-tight. In your case the breakers included are (5) s/p 15's, (5) s/p 20's, (1) 2-p 20, (1) 2-p 40 and (1) 2-p 50. This is a pre-packaged, pre-engineered system and was submitted to UL as designed. I don't mean to de-rail this thread but these questions wers brought up in my contractors association meeting this past week :

• Can these whips be modified in any way without voiding the UL listing ?
• Can the breakers be changed to accommodate the actual circuits needed ?
• If my connection from the transfer switch to the generator is only 10' away am I supposed to coil the extra 20' in the ceiling rafters of the basement ?

Personally speaking, I have modified these whips numerous times and have not been cited for a violation (that's not to say that I'm right). I can't figure out why they use a 2' metallic seal-tight whip for an inside connection. It's a real PITA to work with and if you have to cut it down to accommodate your installation you have to remove the wires anyway. I've changed this to greenfield and again have not been cited. And finally I've changed the circuit breakers to accommodate my customers needs. In many cases I've had no need for a 2-p 20, 2-p 40 or a 2-p 50 breaker. If changing them and the wiring in the whip are violations what would be the right thing to do ? Leave them unused in the sub-panel and safe-off the wiring on the main breaker side ?

From what I know from Generac. The 30 ft whip can be extended 10 ft and still keep its UL listing. But I don't see why the whip cannot also be shortened on the ATS end. As far as breakers go Generac's instructions has a section about changing the factory installed breakers to meet the arc fault code. They state you can buy these breakers at the hardware store. As far as the 2 ft whip I agree it is a pain and don't see a big issue changing it unless you extend it over 2 ft.

 

[Greg1707]

30 foot whip

30 foot whip

How much of the 30 ft whip do you need inside?

I only need about ten feet. I guess I will have to wrap it up and hang in on the wall like a garden hose?

 

[ceb58]

I only need about ten feet. I guess I will have to wrap it up and hang in on the wall like a garden hose?

I would shorten it on the ATS end.

 

[sparky62]

Why do you think it would matter and why do you feel it is such "an important piece of equipment"? Generators are often located a lot more than 5 feet from buildings for many reasons. Size your wire accordingly if necessary.

-Hal

Size it accordingly per code requirements!!

 

[sparky62]

I only need about ten feet. I guess I will have to wrap it up and hang in on the wall like a garden hose?

Why don`t you just use your own , i have to run a 2/3 cable across the house to the other side where the switch is. i`am going to replace the entire 30ft whip!

 

[sullivanelectric]

Whips

Whips

Here's the problem with these units. The 6' whip from the generator to the connection box comes pre-wired. Inside the connection box the power wires are terminated and the control wires have Molex connectors on them. On the transfer switch end the 30' greenfield whip contains the wires that are to be connected to the outdoor connection box. On the far end of the whip the power wires are ring-spaded and the control wires have the matching Molex connectors. The 2' whip that connects the transfer switch to the breaker panel is metallic seal-tight. In your case the breakers included are (5) s/p 15's, (5) s/p 20's, (1) 2-p 20, (1) 2-p 40 and (1) 2-p 50. This is a pre-packaged, pre-engineered system and was submitted to UL as designed. I don't mean to de-rail this thread but these questions wers brought up in my contractors association meeting this past week :

• Can these whips be modified in any way without voiding the UL listing ?
• Can the breakers be changed to accommodate the actual circuits needed ?
• If my connection from the transfer switch to the generator is only 10' away am I supposed to coil the extra 20' in the ceiling rafters of the basement ?

Personally speaking, I have modified these whips numerous times and have not been cited for a violation (that's not to say that I'm right). I can't figure out why they use a 2' metallic seal-tight whip for an inside connection. It's a real PITA to work with and if you have to cut it down to accommodate your installation you have to remove the wires anyway. I've changed this to greenfield and again have not been cited. And finally I've changed the circuit breakers to accommodate my customers needs. In many cases I've had no need for a 2-p 20, 2-p 40 or a 2-p 50 breaker. If changing them and the wiring in the whip are violations what would be the right thing to do ? Leave them unused in the sub-panel and safe-off the wiring on the main breaker side ?

Agreed, they are a PITA to cut down the 2' whips. My questions is how long, if at all, can I add to the 30 ft. whip and still be UL, or code compliant? I realize the AHJ perhaps could even knock down the 30' whip as it comes from Generac. I have terminated the 30 ft into a junction box and continued on with a PVC conduit or flex combo to the outside unit. I always debated with my father(boss) that that is not code compliant as we are altering a UL listed equipment. Anyway there are so many little issues with all brands of gen sets... I mean they are relatively new to the residential market and still working the kinks out.

 

[goldstar]

I've extended these whips 10 or 15' and never had a problem. I've also changed the breaker configurations to accommodate circuits my customers actually needed snd never had a problem. Can't see the need for a 2-P-40 or 2-P-30 on a 14KW unit. Of course you could argue that the unit, as shipped, was put through UL that way and any modification would be a code violation

 

[Greg1707]

generator customization

generator customization

Having just installed my first generator "package" I can attest to the advantages and limitations of the prepackaged units. The attractive feature is that everything is good to go and ready for install. The drawback is having a 24" conduit when what is really needed is a 25" conduit! At the moment there are just two ways to purchase the equipment: ala carte and prepackaged. I wonder if there is a market for a third option: made to order? It would cost more but would be worth the extra cost in saving of time that it takes to assemble all of the materials that are required for a non packaged install.