Dr Mueller Onyx

[Nate_the_Tech]

Be careful moving legs around. Some AC equipment is required to be phased properly. Otherwise the compressor motor will run backwards and cause some serious problems.

[Brian Oshman]

Converting an Onyx is not for inexperienced. The board needs to be completey rewired. The newer ones had a plug and a couple of jumpers to move, the old Onyx will require a skilled tech to perform. No such diagram exists.

The bed does not pull less amps or wattage consumption either, it will simply be divided over three legs instead of two. Watts is watts. You will need to run new wire and will need an additional transformer. Go with #6 wire.

[Nate_the_Tech]

I converted one a few years ago and it wasn't all that difficult. Somewhat involved but with the directions and diagram that do exist made it easier. If I remember it was a matter of adding a breaker and dividing the loads evenly by putting one or two of each circuit on each leg. Like body fans and facials on L1, main fan and bottom lamps on L2, and top lamps on L3. I didn't have to rewire the PCB at least on the year/model I did. The directions/diagram exist, I've had them in my greasy paws a few years ago. Not sure if it was something Lief or Jorgen made up themselves and I somehow got a hold of or what.
And yes there is no reduction of total amp draw but a reduction on two of the individual legs and an increase on the other. This SHOULD fix the problem because he is blowing fuses on on one particular leg.
And as far as having a tech do it I guess that's his call. If his common sense tells him he is in over his head than when he makes that call he will appreciate what we do and not be so hesitant to pay the bill.
Also this conversion is worth the effort if it will fix his problem. Its much easier than the other two choices. Adding a sub panel or selling the Onyx, disassembling the Onyx, buying a new bed and installing it. All of which DOES require an experienced tech and/or electrician.
And according to the NEC Table 310.16. #8 copper conductors allowable ampacities is 50-55 amps depending on type used. THHN is the most commonly used and is rated at 55 amps.

[Nate_the_Tech]

There is no power board on an Onyx.

[Brian Oshman]

Salon owners with very little or no electrical experience, no theory, and no proper tools should not be attempting to rewire beds. It must be done in such a manner to properly distribute the load and not self destruct.

Unless the bed was designed to easily be converted with a simple diagram it should be left to professionals.

I have converted many beds that others were told could not be done and this task is not for amateurs.

To convert an Onyx, you need to rewire the lamp loads, the capacitor banks, and the control circuits and quite frankly, if you are not versed in electrical and electronics procedures and applications then you have no business attempting such a task. This is used in a business and used by many people and it must be safe and reliable.

I would not encourage nor recommend anyone to convert beds that have no experience to do such a task.

As for wire size, most use MC cable, not THHN and conduit. I would run the #6 as if you are going to make an investment in wire upgrade you simply do it once and this allows a future bed upgrade to simply be put in place. No need to have to again upgrade the wiring and the cost of #8 compared to #6 is minimal. Also, Code has changed on breaker rating on #8 and a 40 amp breaker is maximum allowable rating.

Always plan for the future and do it once and do it right the first time.

[Nate_the_Tech]

MC cable is not a wire type, it is a cable. The conductors inside MC cable will most likely be THHN. And MC cable in that size is hard to come across and is very expensive. And I am reading from the 2008 NEC book. I checked the 2011 and no such change has been made. And especially on this application where he is trying to bring his load down to a minimal amount I don't see him installing a 60A or greater bed. Also keep in mind his original raceway was installed for #4 wire this may cause an issue with raceway fill if he uses it.

[Brian Oshman]

I have not read anywhere in this thread where this was a conduit installation. Besides. It will be easier to just abandon the current circuit and run a new one, especially if there are other circuits in the run.

MC is very common and pretty much standard for use in commercial applications. Also, where is it a bad thing to up size the wire a little? This will reduce voltage drop.

#8 with 60ºC insulation would be 40 A max.
#8 with 75ºC insulation would be 50 A max.

[Nate_the_Tech]

I said raceway not conduit. Raceway refers to FMC, RMC, EMT,ENT, PVC ect. If the raceway fill is of code and after a thorough inspection I know no electrician who wouldn't rather fish through existing raceway than have to install new raceways. Also you are correct with the ratings if the wire used and terminations are only rated at 60C. THHN is rated at 90C, Dinrail terminals are rated at 125C and any breaker I have ever used was rated 75C or 60/75C or more. An OCPD using THHN wire derated for 75C should be 50amps.

Am I wrong?
I will admit I am if I am...

[Brian Oshman]

Not saying that you are wrong. It hasn't been established what method of wiring had originally been installed here. Your posts suggest that you are privy to the method used in the location and the OP has not stated any method. It has also not been established if the proper wire size has even been run.

You keep stating that THHN simply could be pulled however no one really knows what is there from the information given. If there is no pipe, raceways, conduit, (all the same, what ever you want to tag it as) then installing pipe would not be very cost effective or practical in a finished space while business is being conducted. It would be much easier to run cable and call it a day. Pulling wire through an existing shared raceway would require shut down (if a raceway exists in this particular installation) as any nick to live conductors can prove catastrophic to the system and personnel if done live. Just because you could do it live doesn't mean that you are supposed to.

Anyway, I am about bulletproof, not bare minimum. Upping to #6 is not a problem. They could always get rid of a bottom feeder® bed in the future for a bigger high end bed so adding wire now will benefit the operation of the existing equipment and allow for flexibility in future decisions without rewiring again. Dr. M likes high voltage. A #8 run will give you a 6 volt drop per 100 ft. A #6 run will give you a 3 volt drop per 100 ft. Skimping on wire skimps on performance. Te time increases 1 minute per every 5 volts loss or underrating from design voltage.

Not trying to bang heads with you, just trying to point out that what you propose probably isn't existing. I find very few salons piped out. Most all are done with MC cable which requires replacement if changes are made.

For others reading this, always plan for the future. Always pull a minimum of 4 conductors to each room. Can be used for three hots, two hots, extra conductor available if a neutral is needed, etc... If you don't need it, cap it off. Being able to swap a bed and a breaker out and move a wire on a buss bar takes much less time than starting over. Can have that bed up and running in a few hours.