# Calculation on breaker

#### floatr

##### Member
I'm upgrading my outside 100 amp panel to the new heat pump an wanted to calculate if I will need a 60 or 50 amp double breaker on the 9.5 kw heat kit.
I have #6 wire .The information on unit/kit says
mca is 49 ,mop is 50 .
.I saw in another post someone spoke on the math % calculation an it looks like I'd need 55 or 60 if 125% applies ---?

I saw this ~
10,000 watts divided by 240 is 41.6 amps. This is a "continuous load" so the wires must have an ampacity of 125% of 41.6 amps, which is 52 amps.Apr 30, 2008

#### curt swartz

##### Electrical Contractor - San Jose, CA
The manufacture has already done the math. 49 amp minimum circuit size and 50 amp maximum overcurrent protection. 50 is your only option.

#### SSDriver

##### Senior Member
Yep, if they list MCA and MOP the only thing you have to look up is conductor ampacity rating to meet MCA, no math(well besides ampacity corrections depending on bundling and temperature, etc).

#### floatr

##### Member
Hmmm I pulled up the same model# of my kit for sale online - hkp 10c online for sale an its requiring 60..--

.copied
Specs page--- Kilowatt9.5 Amperage Requirement (Circuit 1 / Circuit 2)60 / 0 amps Voltage208 - 240 Volts Voltage Phase1 ACCESSORIES

#### floatr

##### Member
It's really odd with another site an all the same specs same Part -saying 50 amp

..Kilowatt(kW):9.5Voltage:208-230VCircuit Breaker Size (Amps):50 Why Buy From Us? RELATED PRODUCTS

#### floatr

##### Member
Pic is off my actual kit-- hkr 10c .
I'm still unsure .but I'm looking at going with the 60amp considering blower start up when EHeat is on .

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#### Jraef

##### Moderator
Staff member
MOP is 50A at 208V, 60A at 240V.

If that confuses you, at 208V the heater elements use less power because of the lower voltage but the same resistance in the element.

#### floatr

##### Member
Thanks yes ,so going by my actual sticker an kit info mine would use the 60 amp breaker ? ..9.5@240 volts like the 1st link had. An is sold with it ?

I guess I'll run#6 @60amp breakers to it.

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#### floatr

##### Member
Also what is the max number of #6 in the 3/4 sch 40 ?