diesel bus block heaters loads

[JustWork]

Has anyone installed outlets, panels, or service for the installation of many outlets for the buses block heaters? I looked at a job where they have just under 50 buses in the yard and they want outlets through out the parking lot. I talked to the bus mechanic requesting information of the heaters and he was not able to answer it at that time. I have several things to figure out and research such as are all block heaters almost equal in wattage, would be considered a continuous load, do we need to figure a them at 125% start up when plugged in? the furthest bank of outlets will be about 900' away,

I will be right up front with everyone I had one heck of a day and I just didn't have the patience to thumb through the book tonight so I figured I'll reach out and maybe it will save me from thumbing through some of those pages.

Just to make everyone :lol: they do have new outlets around the parking lot (not for all of the buses) that were put in last year. Butttt He has an issue that when they plugged some of the buses into the outlets the parking lot pole lights would go out :jawdrop: :roll: see where this is going

 

[fmtjfw]

Been there, done that

Been there, done that

Has anyone installed outlets, panels, or service for the installation of many outlets for the buses block heaters?

Yes

I looked at a job where they have just under 50 buses in the yard and they want outlets through out the parking lot. I talked to the bus mechanic requesting information of the heaters and he was not able to answer it at that time. I have several things to figure out and research such as are all block heaters almost equal in wattage, would be considered a continuous load, do we need to figure a them at 125% start up when plugged in? the furthest bank of outlets will be about 900' away,

I'd treat them as a continuous load.
They are simple resistance loads, unlikely to have much of an initial surge. Also the drivers are going to be plugging them in at "random" not all at 3:22pm.
I put in GFCI receptacles, not breakers and I'd put in a separate GFCI receptacle for each bus -- limiting the number of buses that don't start when a GFCI trips.
I'd do some calculations on the 900' for voltage drop. Can you get more than one service drop and let the POCO help with voltage drop?
The mechanics should know what block heaters they use.

I will be right up front with everyone I had one heck of a day and I just didn't have the patience to thumb through the book tonight so I figured I'll reach out and maybe it will save me from thumbing through some of those pages.

I assume you will be using PVC and LNFC. Use THWN or THWN-2. DO NOT skip installing expansion fittings where the calculations require them. Otherwise the conduit will buckle or break.
Don't use UF.
Expect bus drivers to back into receptacles, poles, panelboards. Expect the extension cords from the buses to the receptacles to be run over.
I found that the GE plastic 3R small panelboards have the required spacing in back for mounting 3R. In WV ice forms between the post and the back of the box. When the ice expands, the result is that the box looks like someone took a hammer to it. I was prepared to put in a vandalism complaint until I found out what really happened. SO use metal 3R boxes.

Just to make everyone :lol: they do have new outlets around the parking lot (not for all of the buses) that were put in last year. Butttt He has an issue that when they plugged some of the buses into the outlets the parking lot pole lights would go out :jawdrop: :roll: see where this is going

The load is going to be at least 30KW (600W/heater minimum)

 

[rcwilson]

On a couple of power plant construction projects in Canada, the parking lots had "bull rails" with outlets for block heaters fed from DP panels that were equipped with a control system that sequenced the power so not all outlets were powered simultaneously. An LED on the receptacle would flash every few seconds to indicate the system was in service. It worked like a forced diversity factor.

It looked like a standard, commercially available system. I was told that local code required a system to minimize power use by block heaters. I never got a chance to open the panels or look at the drawings.

Maybe you can find something like that for the bus yard project. But you could probably make more profit running multiple circuits in a brute force approach.

 

[JustWork]

Thank you

Thank you

I really appreciate the info and they do have a system to control the power to the outlets and currently waiting on the info from my vendor. Once I receive I will post for other should they be interested.
Thank you all
again