United States Commercial Voltages 2

[MarkEFC]

Hi, Wondering if anyone can help me.

Our company have been asked to build and provide a control panel for a commercial swimming pool, along with all the kit (Pumps, UV Unit, Pool Lighting etc.) for a hotel in the United States.

My question is, what is the typical voltage that would be supplied in a commercial building?

Obviously over here (UK), we would build a panel with a 3-phase and neutral supply to it, which can then run both 3-phase items and single phase items.

What is the equivalent to this in the USA?

I apologise if this is a "dumb" question, but i have never come across having to do anything like this before and i dont want to sound stupid to the customer!!

Thanks very much.

 

[crshears]

Then don't ask what the commercial voltages in the US are; ask the customer what the extant power supply is in the hotel. And don't forget they run 60 Hz in the States!

I, also, try not to look stupid, since stupid can't be fixed; but I don't worry about ignorance, as that is easily remedied.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[cranky108]

Swimming pool? Unless you are talking about pumping millions of gallons, I would imagen your control panel will be working with voltages below 600 Volts. So build a panel that can handle single phase for less than 1 HP, and most likely three phase for over 1 HP. Other than that, the relay/contactor coils should be inter changeable with the customer voltage supply.
The motors, lights, and parts outside the control panel will need to match the customers voltage supply.
Single phase motors can be phase to ground, or phase to phase, as well as your lights.

 

[che12345]

"...what is the typical voltage that would be supplied in a commercial building?"
I hope the following information in brief, may be useful?
1. In general, US practice differs from that of UK.
1.1 Attention: All items shall be UL listed. The board shall be UL certified. CE marking is NOT applicable/recognized....etc
2. In UK reference BS 7671. In US reference NFPA/(NEC).
3. Reference NEC " Voltage, Nominal. A terminal value assigned to a circuit or system for the purpose of conveniently designating its voltage class e.g. (120/240 V, 480/277 V, 600V; 60 Hz)".
3.1 Note: It is common " 3-phase, 4-wire wye systems are 480/277 V and 208/120 V ; 60 Hz " .
Che Kuan Yau (Singapore)

 

[cranky108]

che, I wasn't going to give voltages, because that can depend on what the customer has for other applications, and can change from customer to customer.
A packager will likely ask what is available, and work with that. Three phase motors can be ordered for what ever voltage is available, and many single phase motors, and lights can be adjustable between voltages.
The control relays can also be purchased with what ever voltage coil needed, with common sockets used between the different applications.

 

[cranky108]

That said, most likely there is three phase Y grounded voltage available. If a isolation transformer is needed, those are also common. About the only thing I can think of as unusual would be the delta with a center taped ground on one of the transformers. This gives Delta three phase, and single phase, but no Y three phase. This is unusual, but for smaller three phase loads it still exists.

 

[dpc]

Nominal voltages: 120 V (1 ph), 208 V (1 or 3 ph), 240 V (1 or 3 ph but 3ph is uncommon), 480 V (1 or 3 phase). 60 Hz of course.

For typical commercial systems, 208/120 V 3-phase wye is common. For higher loads, 480/277 V. Residential is generally 120/240 V, single phase.

 

[waross]

Residential is generally 120/240 V, single phase.

That would be single family and small apartments.
An apartment building doesn't get very large before the service becomes 120/208 Volt, three phase.
Large high rise apartments may be served at 277/480 Volt, three phase.
Large equipment will be 480 Volt, everything else will be served at 120/208 Volts. Single, three phases or two of three phases.
The neutral point will be grounded on 120/208 Volt systems.
The neutral of 277/480 Volt systems may be directly grounded or impedance grounded.
If any 277 Volt loads are supplied the neutral will be direct grounded.
Note: General area and corridor lighting may be supplied at 277 Volts. In that case, the neutral must be grounded.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[waross]

Be aware that there may be 208 Volts available or there may be 240 Volts available.
It is very rare to find both voltages in the same building.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[cranky108]

And some will have 480/277 delta or wye, and a transformer changing to 208/120 Y. In which case the owner will likely tell you which they prefer you to use.
There are also some homes, located next to larger customers, that will only have 208/120 single phase.

 

[waross]

And some will have 480/277 delta or wye

480 Volt delta? Very rare. Full delta is often problematic.

208/120 single phase

208/120 Volt systems are Not single phase. They are two of three phase systems.
They are rare for single family homes and small apartments. Common for large apartments.



--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[che12345]

"..Our company have been asked to build and provide a control panel for a commercial swimming pool, along with all the kit (Pumps, UV Unit, Pool Lighting etc.) for a hotel in the United States...My question is, what is the typical voltage that would be supplied in a commercial building?..."
I hope the following additional information and proposal may be useful?
1. You had received learned advice on the variation of voltages in the US.
2. My proposal is, it would be more economical to "out source" it to a UL certified fabricator (OEM); in the location of the project. They are familiar with their local requirements/code and are able to answer/resolve issues raise by the approval inspector.
3. Warning: BS and IEC standards are NOT applicable in the US. The NFPA/NEC, UL 508, UL 508A, NEMA, different IP code ... etc. prevail.
Che Kuan Yau (Singapore)

 

[jraef]

There is no "one answer fits all" for commercial properties, it is dependent on a lot of factors, including the size of the property, the availability of sufficient power at the site, what the local utility has in terms of spare transformers to service them, etc. etc. etc. I've done HVAC at a number of resorts in Las Vegas, everything was 480V. I've done stuff for a large resort in the mountains, everything large had to be 240V 3 phase, because that's what the local utility had for spare parts (there was no industrial in that area). I've seen a lot of hotels that use 208Y120, one that had had 2,000A 120/240 single phase service. It just varies too much to make a single decision.

If you want to offer packages like this for North America, you must prepare contingencies for all of the possibilities and be ready to adapt your offering to what each individual customer will need. And be aware, some of them will not know what they need until very late in the project...


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[waross]

You need aoption sheet.
240 Volts Single phase.
208 Volts 3 Phase.
480 Volts 3 Phase.
240 Volts 3 phase. Rare but may often be serviced with the same equipment as 208 Volts 3 phase.
600 Volts 3 phase. Rare but motors and control transformers are readily available.
The customer must choose the proper option.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[jraef]

It’s worth noting that, being pool equipment, I can imagine your motors are likely not large. If we are talking about 5HP and under, 3 phase motors built for North America (NEMA spec) are usually made as what’s called “tri-volt”, meaning 208-230/460V, which would cut down your required options because 208-240V could be virtually the same (other than overload settings). 480V would require different control and protection devices though. This option may not be available for motors built as IEC type and adapted to use here, it’s more of a NEMA design criteria. But you should be able to access them.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[resqcapt19]

Attention: All items shall be UL listed. The board shall be UL certified. CE marking is NOT applicable/recognized....etc

While a lot of equipment installed in the US is required to be listed, there is no requirement that it be listed by UL (Underwriters Lab. There are multiple listing agencies that can list equipment for use in the US. One list of such agencies can be found at OSHA, as they maintain a list of National Recognized Testing Laboratories. Even though another agency is doing the testing, the vast majority of the product standards that equipment is listed to are published by UL