19
Mar
10 is good to go. Calculated Load Minimum Insulated Copper Wire Size Based on Type up to 3 Conductors in a raceway or cable 2 Next Size Up.
If it is 20 amps or less the 12 wire is fine.
Minimum circuit ampacity wire size. Ampacity is the measurement of the maximum amps of current that can flow through the wire before it starts to deteriorate. A circuit is a chain of electronic components connected by conductive wire. Thus minimum circuit ampacity MCA is the minimum wire size that can be used to safely wire electronic products.
Calculating the MCA requires other electrical information from the components in the circuit. For example a max fuse size of 15A and a minimum circuit ampacity of 97A. Would I be able to use 16AWG wire ampacity 14A.
It is a 120V circuit. 16 AWG is not an option 14 AWG with 15 amp fuse would be acceptable. Minimum Circuit Amps MCA is a calculated value that specifies the minimum main power wire size.
More specifically MCA is the highest steady-state electrical current that the rooftop unit should see when operating correctly. The minimum circuit ampacity MCA is also used to figure the minimum wire size required for a field wired product. It is chosen to guarantee that the wiring will not overheat.
The wire is protected by Overload protection either in the motor or in the air handler equipment. The 50 amp breaker is for short circuit and ground fault protection only. The larger breaker is sized this way to allow the motor to start with LRC locked rotor current and not trip the breaker.
You will need a 25A or 30A breaker. Id recommend 30A if it were me. As per CEC 14-104 2 minimum wire size is 10.
12 is only good for a 20A breaker. This is unrelated to voltage drop. Actual running amps is only about 80 of the MCA - 20A.
50ft is not long enough to worry about voltage drop. 10 is good to go. MCA is not the running load of the condenser.
So yes you can have a 14 gauge wire and 15amp breaker on an MCA of 142amps. MCA is the min circuit allowed. Not the load on the circuit.
MCA is calculated by compressor RLA times 125 plus condenser fan motor RLA. The RLA of a compressor in a condenser with a MCA of 14amps is about 8 or 9 amps. Ampacity reduction of THHN 90C conductor is based on the conductors ampacity as listed in the 90C column of Table 310-16 and not on the terminal temperature rating.
Branch Circuit Continuous Load Example. What size branch-circuit overcurrent protection device and conductor THHN is required for a 19 kVA of nonlinear loads 75C terminals. With a minimum circuit ampacity of 293A you are fine with 10 wire in most cases that do not involve very long wire runs.
The unit should have a 50A breaker to prevent nuisance trips. Section 31016 Conditions of Use. Such as conductor voltages between 0 - 2000V conductors rated 60C 75C or 90C wiring installed in a 30C ambient temp and having not more than 3 current carrying conductors.
Calculated Load Minimum Insulated Copper Wire Size Based on Type up to 3 Conductors in a raceway or cable 2 Next Size Up. Twelve-gauge wire is good for 20 amps 10-gauge wire is good for 30 amps 8-gauge is good for 40 amps and 6-gauge is good for 55 amps and The circuit breaker or fuse is always sized to protect the conductor wire. To determine the minimum supply circuit ampacity on the nameplate the manufacturer will use the formula of RLA x 125 Other Loads.
Can 12 gauge wire handle 30 amps. A 30-amp breaker does not operate safely with a 12-gauge wire. The minimum wire size that is allowable for use with a 30-amp breaker is 10 gauge.
If this is a new unit check the data plate for the Minimum Circuit Ampacity MCA. If it is 20 amps or less the 12 wire is fine. Then check the Maximum Overcurrent Protection MOCP or Max Fuse Size.
Wire size should be determined in accordance with National Electrical Codes. Extensive wire runs will require larger wire sizes.
The conductors between the drive and the motor shall have an ampacity equal to or larger than 125 percent of the motor full-load current as determined by 4306 A or B. There is an exception to this when the power conversion equipment is listed and marked as.
Minimum Circuit Ampacity The minimum circuit ampacity MCA is the minimum wire size required for a field wired product. It is chosen to guarantee that the wiring will not overheat under the expected operating conditions. The wire size takes into account the normal current draw ageing of components and anticipated faults.
Minimum Circuit Amps MCA is a calculated value that specifies the minimum main power wire size. More specifically MCA is the highest steady-state electrical current that the rooftop unit should see when operating correctly. The minimum circuit ampacity MCA is also used to figure the minimum wire size required for a field wired product.
Similarly the Minimum circuit ampere is 122 A it means that the value of MCA is 122 A. Thus we can select the minimum size wire as per the MCA rating. The value of LRA and FLA of the fan motor is also provided.
Up to the nearest standard fuse size typically a multiple of 5. In other words the MOP shall not be less than the MCA. If the MOP is less than 15 it shall be rounded up to 15 amps.
This is the minimum size of fuse or circuit breaker permitted by code. Lighting and appliance branch-circuit panel boards and the feeder conductors to a dwelling unit shall not be required to be larger than their service entrance conductors. The grounded conductor shall be permitted to be smaller than the ungrounded conductors provided the requirements of Sections 2152 22022 and 23042 are met.
Minimum Circuit Ampacity MCA is a calculated value that specifies the minimum main power wire size. It is also used to determine the minimum wire size required for a field wired product. This specification is necessary in order to guarantee that the wiring will not overheat under expected operating conditions.
The minimum circuit ampacity is listed at 124A. Using Table 2 and the 60C column we could use 142 wiring. Factoring in the voltage drop we can.
Minimum Circuit Ampacity MCA The MCA value tells us how big the wire needs to be. Generally if the minimum circuit amperes is 149 amps then you need a 14-gauge wire. If the electrical label says its a 151 MCA mini-split you need a 12-gauge wire and if its a 34-amp MCA mini-split requires an 8-gauge wire.
Branch-circuit conductors shall have an ampacity not less than the maximum load to be served. Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads the minimum branch-circuit conductor size before the application of any adjustment or correction factors shall have an allowable ampacity not less than.