Wire Size For 50 Amp Service

This service is wired the same as the tt 30 120v except for the larger 50 amp single pole breaker.

Wire size for 50 amp service. 40 x 1 25 14 3 50 14 3 67 amps. This is a 120 volt service not a 120 240 volt service we normally associate with 50 amp. For a 50 amp aluminum wire use no 4 awg. 6 is only good up to 40 amp.

Aluminum wires are rated differently than copper wires. A 50 amp service is not a 30 amp service and a 20 amp service joined together. Aluminum wires come in different types. Types thwn and rhw are the most commonly used ones.

I used to be a manager at home depot. The smaller the number on the wire the larger the wire diameter. 60 c 140 f 75 c 167 f awg mm copper. Nema 5 50r 2 pole 3 wire grounding rated 50a 120v.

Here is what steve had to say. We typically sold 6 wire for a 50 amp load. If you check the voltage drop for the 6 above at 145ft is 5 73 volts so if its 220v then at the end you will have 214 27v vdrop ir. Even the largest rvs when plugged into 50 amp service still almost universally use this double hot pole or double bus installation to draw only 120 volts to two separate 120 volt circuits simultaneously thereby accessing a possible 12 000 watts of power.

Steve needed to run 50 amp service from his main panel in his home to a 100 amp breaker box shown below in his new shop. The 5 50 120 volt service is uncommon twist locking plugs and receptacles are generally used for this type of high current applications. Steve purchased our 6 awg thhn thwn copper building wire for his project. The wire size chart below shows allowable ampacities of insulated conductors rated up to and including 2000 volts 60 c through 90 c 140 f through 194 f not more than three current carrying conductors in raceway cable or earth directly buried based on ambient air temperature of 30 c 86 f.

However the reality is that all but the largest all electric motorhomes use far. The tables below are intended to be a general guide for wire size and amp ratings. Allowable voltage drop the calculator allows entry of a voltage drop but caution should be used when doing so to make sure you are calculating the wire sizes in accordance with nec article 210 19 fpn no. If that is to much then use.

Common sizes include 14 12 10 8 6 and 2 gauge wire. If every rv with a 50 amp plug actually used anywhere near 50 amperes per leg of the 240 volt connection then 4 wire would be recommended to minimize voltage drop. Wire gauge refers the physical size of the wire rated with a numerical designation that runs opposite to the diameter of the conductors in other words the smaller the wire gauge number the larger the wire diameter.