Wiring My First Hot Tub

[mkgrady]

The unit is a Sundance 880 Series, Optima. It requires a 60 amp circuit, 240 volts (not 120/240). It will be installed outside a single family home. The owner is going to make a concrete pad for it before it is delivered

6-2 NM from a 60 amp gfci in the main panel to a disconnect on the outside of the house. Disconnect will be >5 feet from tub and < 50 feet from tub and within sight

Bury PVC conduit from the disconnect to the tub with #6THHN, two hots and insulated ground to tub control box

Any metel within 5 feet of tub will be connected together and to the tub bonding lug

It is normal to have the conduit run right into the open space under the tub? Or is it normally run to the outside of the tub and flex into the open area. I'm having trouble picturing how to have the PVC come out of the ground and next to the tub and somehow getting it into the conduit entrance hole.

I don't know if the pad will be getting reinforcing rods. If it does I will bond them along with any other metal within 5 feet. I am confused about whether or not I also have to run a wire around the perimeter of the tub. If so would it be layed into the concret or just buried a few inches into the dirt around the perimeter of the pad?

Am I missing anything? All corrections and sugestions welcome. Thanks

 

[kwired]

The unit is a Sundance 880 Series, Optima. It requires a 60 amp circuit, 240 volts (not 120/240). It will be installed outside a single family home. The owner is going to make a concrete pad for it before it is delivered

6-2 NM from a 60 amp gfci in the main panel to a disconnect on the outside of the house. Disconnect will be >5 feet from tub and < 50 feet from tub and within sight

Bury PVC conduit from the disconnect to the tub with #6THHN, two hots and insulated ground to tub control box

Any metel within 5 feet of tub will be connected together and to the tub bonding lug

It is normal to have the conduit run right into the open space under the tub? Or is it normally run to the outside of the tub and flex into the open area. I'm having trouble picturing how to have the PVC come out of the ground and next to the tub and somehow getting it into the conduit entrance hole.

I don't know if the pad will be getting reinforcing rods. If it does I will bond them along with any other metal within 5 feet. I am confused about whether or not I also have to run a wire around the perimeter of the tub. If so would it be layed into the concret or just buried a few inches into the dirt around the perimeter of the pad?

Am I missing anything? All corrections and sugestions welcome. Thanks

According to 334.80 NM cable is to be sized according to 60?C rating in ampacity charts. 60? 6AWG is only rated 55 amps.

680.26 Equipotential Bonding. Read that section before they pour the concrete - you will want reinforcing bars or your own equipotential bonding installed if there is no reinforcing bars.

 

[augie47]

The unit is a Sundance 880 Series, Optima. It requires a 60 amp circuit, 240 volts (not 120/240). It will be installed outside a single family home. The owner is going to make a concrete pad for it before it is delivered

6-2 NM from a 60 amp gfci in the main panel to a disconnect on the outside of the house.

Some tubs require a FULL SIZE equipme t ground

Disconnect will be >5 feet from tub and < 50 feet from tub and within sight

Not requiredd on S/F dwellings

Bury PVC conduit from the disconnect to the tub with #6THHN, two hots and insulated ground to tub control box

Any metel within 5 feet of tub will be connected together and to the tub bonding lug

It is normal to have the conduit run right into the open space under the tub? Or is it normally run to the outside of the tub and flex into the open area. I'm having trouble picturing how to have the PVC come out of the ground and next to the tub and somehow getting it into the conduit entrance hole.

Most I see have surface run conduit changing to flex

I don't know if the pad will be getting reinforcing rods. If it does I will bond them along with any other metal within 5 feet. I am confused about whether or not I also have to run a wire around the perimeter of the tub. If so would it be layed into the concret or just buried a few inches into the dirt around the perimeter of the pad?

See 680.26

Am I missing anything? All corrections and sugestions welcome. Thanks

 

[Gac66610]

The unit is a Sundance 880 Series, Optima.

Bury PVC conduit from the disconnect to the tub with #6THHN, two hots and insulated ground to tub control box

I don't know about the tub you are installing, but most i have done need two hot conductors, a grounded conductor, and a ground. yours may not... just what i have seen

 

[mkgrady]

I don't know about the tub you are installing, but most i have done need two hot conductors, a grounded conductor, and a ground. yours may not... just what i have seen

The installation instructions are real clear that it is only two hot wires and an EGC

 

[mkgrady]

According to 334.80 NM cable is to be sized according to 60?C rating in ampacity charts. 60? 6AWG is only rated 55 amps.

680.26 Equipotential Bonding. Read that section before they pour the concrete - you will want reinforcing bars or your own equipotential bonding installed if there is no reinforcing bars.

With a wire rated 55 amps don't I get to go to the next standard size breaker? Isn't that a 60?

Assumming there will be reinforcing in the concrete pad it looks like I have to bond it and run bare #8, 4-6 inches deep, 18-24 inches from the water edge and circle the entire tub.

 

[mkgrady]

Some tubs require a FULL SIZE equipme t ground
Not requiredd on S/F dwellings
Most I see have surface run conduit changing to flex
See 680.26

I did not see any mention of a full size EGC in the wiring instructions. If I find that to be the case I guess I will have to run THHN in conduit.

I thought the emergency shut off was exempted from S/F dwelling but that a disconnect is still required.

Once I see the site I will know better on the conduit/flex/entrance question. The owner seemed to indicate that the tub will be a ways from the house so UG conduit is the only way to get there. I'm still stumped on how to transition from UG conduit to the entrance which seems to be just a couple of inches off the ground.

 

[infinity]

Yes, a disconnect is still required within sight of the tub. And yes you can go up to the next standard size of 60 amps if the connected load is 55 amps or less.

 

[John120/240]

Could you-Is it allowed; Come up underneath the tub like is done for switchgear ? Location

has to be dead on to work right. Stub up for a PVC j-box then run flex as Augie said.

 

[stickboy1375]

Could you-Is it allowed; Come up underneath the tub like is done for switchgear ? Location

has to be dead on to work right. Stub up for a PVC j-box then run flex as Augie said.

Nonsense, plenty of room to stub up under the tub, then just transition to flex to the control box..... BUT, make sure you look at the tub before you attempt this... I do this method all the time actually.

 

[kwired]

Yes, a disconnect is still required within sight of the tub. And yes you can go up to the next standard size of 60 amps if the connected load is 55 amps or less.

If it is a continuous load the current must be less than 44. (edit 44 or less) That will make the minimum ampacity be 55. Is a hot tub a continuous load?

When first filled probably takes more than 3 hours to heat it to normal temperature I would guess.

 

[infinity]

If it is a continuous load the current must be less than 44. (edit 44 or less) That will make the minimum ampacity be 55. Is a hot tub a continuous load?

When first filled probably takes more than 3 hours to heat it to normal temperature I would guess.

I say that it is not a continuous load by the definition in Article 100. To be a continuous load it would need to operate at it's maximum ampacity for 3 or more hours. That means that every light, heater, pump, etc. would need to be on simultaneously and continuously for 3 or more hours.

 

[kwired]

I say that it is not a continuous load by the definition in Article 100. To be a continuous load it would need to operate at it's maximum ampacity for 3 or more hours. That means that every light, heater, pump, etc. would need to be on simultaneously and continuously for 3 or more hours.

Fill that tub with 50?F water and tell me it doesn't take more than 3 hours to raise the temp 50?+. Unless it is a really big heater for the capacity of water in the tub. Maybe the water is not so cold where you live.


edit to add:

You probably have less current when in heat mode only as only one pump (if multiple pumps) may run or it/they only run at a low speed. Lights in these things are LED's and mean almost nothing when it comes to total current of the unit.

 

[marti smith]

I say that it is not a continuous load by the definition in Article 100. To be a continuous load it would need to operate at it's maximum ampacity for 3 or more hours. That means that every light, heater, pump, etc. would need to be on simultaneously and continuously for 3 or more hours.

If it was operated for more than 3 hours, would the manufacturers instructions already have this covered?

 

[infinity]

Fill that tub with 50?F water and tell me it doesn't take more than 3 hours to raise the temp 50?+. Unless it is a really big heater for the capacity of water in the tub. Maybe the water is not so cold where you live.


edit to add:

You probably have less current when in heat mode only as only one pump (if multiple pumps) may run or it/they only run at a low speed. Lights in these things are LED's and mean almost nothing when it comes to total current of the unit.

It does mean that it's not a continuous load if any one component is not on at it's maximum ampacity for the 3 or more hours along with everything else.

 

[mkgrady]

If it is a continuous load the current must be less than 44. (edit 44 or less) That will make the minimum ampacity be 55. Is a hot tub a continuous load?

When first filled probably takes more than 3 hours to heat it to normal temperature I would guess.

With the pumps blower and heater all on it draws 48 amps. Is it reasonable to assume they would all be on continuosly for more than two hours? Don't people wait to get in the tub before turning on the blower?

 

[kwired]

If it was operated for more than 3 hours, would the manufacturers instructions already have this covered?

We really don't know. There seems to be no real standard from what I have seen unlike HVAC units that do have continuous load values factored in their nameplate. They call it Minimum circuit ampacity and maximum overcurrent protection. Hot tubs are never that specific with their information. There is another current thread that has a little bit of this confusion as part of the topic of discussion. Plate says 40 amps current, but also says 6 AWG minimum conductor and 50 amp overcurrent device. I assume that one is figuring in the 125% for continuous loading as it would work out to needing 50 amp conductor and 50 amp overcurrent - but 8AWG should be acceptable conductor as long as it is 75? conductor.

 

[infinity]

We really don't know. There seems to be no real standard from what I have seen unlike HVAC units that do have continuous load values factored in their nameplate. They call it Minimum circuit ampacity and maximum overcurrent protection. Hot tubs are never that specific with their information. There is another current thread that has a little bit of this confusion as part of the topic of discussion. Plate says 40 amps current, but also says 6 AWG minimum conductor and 50 amp overcurrent device. I assume that one is figuring in the 125% for continuous loading as it would work out to needing 50 amp conductor and 50 amp overcurrent - but 8AWG should be acceptable conductor as long as it is 75? conductor.

Is the MCA real there as a continuous load value?

 

[kwired]

Is the MCA real there as a continuous load value?

MCA on a heat pump or AC unit is figured exactly the way you are supposed to figure it yourself if you were to assemble same value of components yourself to build a similar machine.

It is 125% of rated load of largest motor (or compressor) plus 100% of all other load. I have not seen one yet that I investigated that was not the same value as it would be if you calculated it that way yourself.

I guess to be real value of continuous load it needs to be 125% of all load - yet this is how motors - multi motors, and motors with other loads are calculated according to 430. The hot tub is similar except the heater is usually larger load than any motors. Maybe I don't fully know what I am saying.

 

[infinity]

MCA on a heat pump or AC unit is figured exactly the way you are supposed to figure it yourself if you were to assemble same value of components yourself to build a similar machine.

It is 125% of rated load of largest motor (or compressor) plus 100% of all other load. I have not seen one yet that I investigated that was not the same value as it would be if you calculated it that way yourself.

I guess to be real value of continuous load it needs to be 125% of all load - yet this is how motors - multi motors, and motors with other loads are calculated according to 430. The hot tub is similar except the heater is usually larger load than any motors. Maybe I don't fully know what I am saying.

I got what you're saying.