shop/office calc

[Ktmbowhunter]

Hey there folks....I'm currently trying to bid a shop but there are a few things holding me up. This has a 50' x 75' welding/working area with an additional 25' x 50' office area so the total dimensions are 50' x 100'. There are 3 batrooms complete with EF's, 2 lamp 2 x 2's, and GFCI. The service is a 400A 1ph 240V.

Im using 15-6 lamp T5HO's in the fab area. There are 3 welding outlets, 25 duplex & GFCI's, 1-240V 3Hp compressor, and 3-240V 3/4Hp overhead doors. On the exterior there are 4 LED wallpacks that draw very little. He plans on installing a 31.5kW electric boiler for floor heating.

The office has a kitchen complete with fridge, microwave, and range. None of these I have info on so I figured 12.5kW on the range, 1000W on the microwave, and 800W on the fridge. There are 14-2 lamp T8's that are 1.85A, 3-2 lamp T8's in the bathroom at about an amp a piece, The exhaust fans are 3 amps, and 31 duplex/GFCI's. I have no info on the water heater or the A/C.

I'm concerned that I will be cutting it close after the installation of the A/C and water heater arrive. I'm approximately 200' from the meter. I was planning on going underground with parallel 4/0 THHN. All the help is much appreciated!

 

[kwired]

Hey there folks....I'm currently trying to bid a shop but there are a few things holding me up. This has a 50' x 75' welding/working area with an additional 25' x 50' office area so the total dimensions are 50' x 100'. There are 3 batrooms complete with EF's, 2 lamp 2 x 2's, and GFCI. The service is a 400A 1ph 240V.

Im using 15-6 lamp T5HO's in the fab area. There are 3 welding outlets, 25 duplex & GFCI's, 1-240V 3Hp compressor, and 3-240V 3/4Hp overhead doors. On the exterior there are 4 LED wallpacks that draw very little. He plans on installing a 31.5kW electric boiler for floor heating.

The office has a kitchen complete with fridge, microwave, and range. None of these I have info on so I figured 12.5kW on the range, 1000W on the microwave, and 800W on the fridge. There are 14-2 lamp T8's that are 1.85A, 3-2 lamp T8's in the bathroom at about an amp a piece, The exhaust fans are 3 amps, and 31 duplex/GFCI's. I have no info on the water heater or the A/C.

I'm concerned that I will be cutting it close after the installation of the A/C and water heater arrive. I'm approximately 200' from the meter. I was planning on going underground with parallel 4/0 THHN. All the help is much appreciated!

the electric boiler is the major thing here, you need about 130 amps for that - that leaves you 270 for everything else - without further calculations and based on most of those type of places I've been involved with I'd say you likely have plenty of capacity. You have a lot of items but not too many that are loaded for extended periods of time, even if art 220 says you are pushing it, in many cases you never draw that heavy of a load for very long. A/C probably is insignificant as it likely doesn't run when the boiler does and it probably will be well under 130 amp load. I know some will say you need some sort of assurance the AC and boiler will not operate at same time - I sort of get that - but reality still sets in and if they are running at same time maybe it isn't all that bad if something is overloaded and trips to get someones attention that something isn't right - though I still think that chance isn't very good anyway.