Whole house generators

[renosteinke]

Sorry, kwired, you misunderstand the code requirement for the transfer switch.

Remember, the switch is expected to perform under a 'full load.' The house service size is defined as the amp rating of your main disconnect. The genny size is defined by the nameplate. The switch has to be able to switch both.

Thus, a house with a 200 amp service and a 125 amp genny will need a 200 amp transfer switch- even if the house calculates at 125 amps and you never measure more than 90 amps with everything running.

 

[kwired]

Sorry, kwired, you misunderstand the code requirement for the transfer switch.

Remember, the switch is expected to perform under a 'full load.' The house service size is defined as the amp rating of your main disconnect. The genny size is defined by the nameplate. The switch has to be able to switch both.

Thus, a house with a 200 amp service and a 125 amp genny will need a 200 amp transfer switch- even if the house calculates at 125 amps and you never measure more than 90 amps with everything running.

I guess if I read the title of the thread I am off topic. I fully understand what you just said, my statement was aimed at an installation where the transfer switch only transfers selected loads, but title of thread suggests we are transfering everything, my bad.

I will add that consideration of only transferring selected loads or shedding certain loads may be well worth it when considering cost of a generator or the transfer switch.

 

[andyselec@aol.com]

Unless someone is in an area that has frequent outages and are on a well, whole house generators aren't worth the expense. They require a heavy sales pitch because of the install, operating and maintence cost. They need their oil changed 2-4 times a yr, filters and plugs annually. One customer need one for health reasons so I used to service it for them at a steep discount( barely covered cost and I might of made $10 for the 1.5 hr) because they where elderly and sick. For me it was a learning experience. Square D makes a combo meter /panel that you can get a whole house manual transfer kit for (lowes started stated selling a panel with kit for $199) it makes for a nice and safe transfer using male outlet and normal male / female cord. It is the only meter panel I use because some of my customer are on well's and they discover how important electricity is for getting themselves water. Even Doing a service change (using the above mention panel) and buying a portable generator would be cheaper than a whole house one.

 

[kwired]

Unless someone is in an area that has frequent outages and are on a well, whole house generators aren't worth the expense. They require a heavy sales pitch because of the install, operating and maintence cost. They need their oil changed 2-4 times a yr, filters and plugs annually. One customer need one for health reasons so I used to service it for them at a steep discount( barely covered cost and I might of made $10 for the 1.5 hr) because they where elderly and sick. For me it was a learning experience. Square D makes a combo meter /panel that you can get a whole house manual transfer kit for (lowes started stated selling a panel with kit for $199) it makes for a nice and safe transfer using male outlet and normal male / female cord. It is the only meter panel I use because some of my customer are on well's and they discover how important electricity is for getting themselves water. Even Doing a service change (using the above mention panel) and buying a portable generator would be cheaper than a whole house one.

They take a pretty big jump in price when you go from the largest air cooled unit available to a not so much higher capacity but is liquid cooled unit. That size is usually right around the 16-20 kW range right at capacity needed or desired in many cases.

The 2-4 oil changes per year is just because of running it for weekly excercising, if you actually have frequent outages you will change oil even more often.

 

[Greg1707]

100 amp and 200 amp transfer switches on 14 kw generators

100 amp and 200 amp transfer switches on 14 kw generators

I noticed that 14 kw generators are sold with 100 amp or 200 amp transfer switches. The machines produce 58 amps. What is the purpose of the 200 amp switch? It can't be used as service equipment can it when the machine is only 58 amps?

 

[kwired]

I noticed that 14 kw generators are sold with 100 amp or 200 amp transfer switches. The machines produce 58 amps. What is the purpose of the 200 amp switch? It can't be used as service equipment can it when the machine is only 58 amps?

The generator can supply a panel that is supplied with 200 amp circuit, but can not supply actual 200 amps of load. There has to be a way of managing the load when supplied by the generator. A manual transfer switch means the user manually is selecting the load that is connected.

An automatic transfer switch also needs automatic load management if the generator can not supply the connected load otherwise if it all automatically transfers the generator will be overloaded and overcurrent devices will open making the whole point of automatic standby transfer pretty much pointless.

Now if the necessary demand of standby power is more than 58 amps you need to select a larger generator.