BREAKER PROTECTION.

[laz 57]

HI GIZ,

  I was just reading the wire question and asked myself about the breaker protction.  I am running all my transformers, 2 modern ZW with 8, 180watt blocks and 2 CW 80 watters.  That gives me1440 watts with the ZWs and another 160 watts with the CW for a total of 1600 watts.  To find the amperage I divide the volts 120 into 1600, which gives me 13.3 amps.  I have a 20 amp breaker in and all is wire in 14 ga. stranded.  Is this good?

Thanks,

laz57

[phillyreading]

laz 57,

Are you talking about power to the transformers from the wall outlet or power to the tracks?

If from the wall outlet it should be 15 amps on 14 gauge wire, 20 amps on 12 gauge wire.

Lee F.

[laz 57]

LEE it is from the wall outlet.  I have it wired with 12 ga. and its on a 20 amp breaker.

laz57

[A&Y Ry]

At 1600 watts consumption you are far below the 2400 wattage/20 amp rating of your #12 household circuit. It is good to stay about 1-2% below the wires's capacity rating.

[Wes Whitmore]

If you have 12ga all the way to the 15 amp breaker, I would say the wire size is fine.  The breaker will trip long before you exeed the wire rating, which is how it is supposed to happen.  Do you guys see a problem with upgrading to a 20 amp breaker on that circuit if he needs it?

Wes

[lionelsoni]

"I have a 20 amp breaker in and all is wire in 14 ga. stranded."

"I have it wired with 12 ga. and its on a 20 amp breaker."

Which is it?  In any case, protect 12 AWG at 20 amperes and 14 AWG at 15 amperes.

Is the circuit breaker the one protecting the outlet that the layout is plugged into, or is it a separate circuit breaker used just with the layout?

There are two types of plugs that you might be using.  A 20-ampere plug has one of the two blades rotated at right angles to the other.  With that plug you should use at least 12 AWG and not draw more than 16 amperes.  A 15-ampere plug has the two blades parallel to each other.  With that plug you should use at least 14 AWG and not draw more than 12 amperes, regardless of whether the outlet is on a 12 AWG, 20-ampere branch circuit.

Your power calculation is clearly for the worst case.  It is highly unlikely that you would be drawing the full rated power for all of your transformers simultaneously, or anything at all close.  I would consider your total load to be less than 12 amperes.

[luther_stanton]

Laz 57,

If I read your aboving postings correctly, you were talking about protection from the wall to the transformers. I also use Scott's Odds N Ends breaker on the feed from the tranformer to the track.  I have my power distributed to my tracks in 4 blocks (through TPCs) and have a I used the CB4-10 part number which gives eack block 10A protection. 

I think these are good protection in addition to any breakers on the wall power feeds. I know these work as they have blown during derailments.

[laz 57]

GIZ, as LIONELSONI wrote..

Is the circuit breaker the one protecting the outlet that the layout is plugged into, or is it a separate circuit breaker used just with the layout?

Yes the circut breaker is the one protecting the outlet that the layout is plugged into.

I have the outlet wire at 12 gauge and I have a 20 amp breaker for that outlet.  There is nothing else on it.  I think what I have heard so far is that should be good enough?

laz56

[twaldie]

Hi Laz,

In your calculations you appear to be assuming 100% efficiency in your transformers.  I would think they would be somewhat less than 100, so your current on the input side would be higher.  The high current would only occur if you ran all of your transformers at full output, though..... if you are you have one huge layout!  If your breaker isn't (is'nt?) tripping you are probably OK.

Tim 

[laz 57]

THANKS GIZ,

   With all the advise I trhink i'm ok with a 20 amp breaker to the outlet that gets plugged into the layout.  Thanks again.

laz57