Tanning Salons

[finster1]

I work in alot of tanning salons and the panels in these always seem to be overloaded by design. The engineer on the last salon said he did the calculations, and with diversity he took into consideration the time to undress the actual time spent tanning the time to redress, and that the bed could only be used 3 times an hour and that is why he could add over 400a of service to these 3ph panels on a 200a main panel. Can anyone explain this to me in english if they understand the Electrical Engineers Explanation for this.I am still confused but all of these tanning salons seem to have the same situation. I realize that these beds wont all be on at the same time ,but what if they are. Also in the summer time the nominal voltage of 208v drops and these are all hooked up on buck boost most 3ph with dual transformers they cook breakers frequently. I tryed to explain to the owners that I feel the low incoming is causing the breakers to be overloaded......Lower voltage...higher amperage..in some cases exceeding the rating of the breakers....One particlar chain has these ht60 beds on 70a and in the summer they sit at 73 amps.The ht54 are on 60a and in the summer they sit at 64a. Any explanation or clarifications on my findings appreciated.

Licensed Electrical Contractor NJ
Jimmy P

 

[frenchelectrican]

i am not sure but i can tell you one thing if take a load figures the tanning beds what i do is figure them as contouns useage and also you have to factor in with the A/C load those tanning bed can crank pretty good amount of heat in winter time it not too bad but summer time it will take alot of A/C to keep them in conftable tempture.

and keep in your mind that if the POCO transformer supply not only that place but other building as well you have to understand that on very hevey power useage the voltage will drop some degree but how much i dont know depending on the system it set up.

Merci, Marc

i will let other chime in too if have more info with this details

 

[kingpb]

What is described sounds ludicrous. Just because they can only be used 3 times in 1 hour doesn't mean that they won't all be used at the same time, which will cause an overload on the panel and the breaker will trip. Certainly, there probably is some reduction that can be possible based on the fact that they won't all be concurrently running, but not 50%. I would have to see the actual calcs but on the outset I would have to invoke the BS rule. Keep in mind that even if they are non-continuous, the protective device still has to be rated for the full amount of non-continuos load.

 

[LawnGuyLandSparky]

Sounds like the work of a "value engineer" not an electrical engineer... and the proof is in the history of burned up breakers.

The irony is that if everything was done correctly from the onset, you wouldn't "work a lot in tanning salons."

 

[dbuckley]

Diversity is good, and is an essential part of calculating the real load requirements, but this seems to be a case where the "engineer" has gone too far in his calcs. Worse, he seems to have got the actual consumption of the beds wrong, and that's an error you would growl at an apprentice for.

The other side of this coin is that the PoCo boys have a feel for how conservative their NEC governed EC colleagues are in terms of their load calcs, and thus have generated rules of thumb for how much to derate what the EC says to deliver an appropriately rated supply. If Sunbed World always loads up to something close to what the panel is rated at, then the PoCo boys estimation will also be wrong, leading to PoCo tranny overload and consequent voltage droppage.

 

[mdshunk]

Fact of the matter is, in the summer, these salons can very often have most or all the equipment running at the same time. They normally have a 3 to 5 minute timer that starts them automaticly when the customer is typed in as having arrived the bed management computer. Typical sessions are 12-15 minutes. Typical dressing time is 5 minutes, and it takes the attandant from 1 to 2 minutes to clean the bed and replace the linens. In the summer, this is a nonstop event.