Upgrading old load center to 200A

[Wolfeie]

Hello,

I have a small cabin built in 1930 up in Cripple Creek, Colorado. Altitude 9494'.

The current electrical systems were installed in the early '60's with an FPE main lug load center panel and a bunch of 20A breakers where some are double tapped. It is my intent to replace the exterior load center with a 200A main breaker load center to not only eliminate the double tapps but to add an electric tankless water heater that requires 3-50A circuits (yeah, the winter incoming water is way cold). The house wiring is all romex (looks to be 14-2) with very few of the plugs grounded...

I have the following questions:
1. Wire from the meter to the load center needs to be CU 2/0 and be a Red/Black/White
2. I drive a grounding rod, 8', all the way into the ground and tie the rod to the panel. Do I need to do anything specific to the circuits running into the house (note item #3) regarding grounds? Is it ok to now ground these circuits.
3. Eliminate all double tapps to new breakers at 20A or less each
4. Can I run 3-50A, 8ga wire, circuits in a single conduit the 12' from the panel to the tankless water heater? If so, what is the right size conduit?

I would consider myself an expert DIYer and am not afraid of replacing the panel and running the new circuits assuming that I understand wire size, etc. I sincerely appreciate your help and recommendations!

[HayZee518]

50 amp circuits require no 6 cable, romex or thhn/thwn. federal pacific is NOT to be used simply because its branch breakers will not trip on a fault current. tests have proved them selves that a load on a 20 amp breaker will not trip within 3 cycles as advertised but exceed 90 amps before anything happens. get a GE or Crouse-Hinds panel. Most of their breakers are interchangeable. a 200 amp panel needs a 4/0-3 SEU Aluminum cable. Copper is price-wise prohibited although if you want to incur the cost, it's up to you. anti-oxidant is needed on all conductors. besides a water pipe ground, you'll need to drive two ground rods about four feet apart, full length into the ground with a continuous loop between them and the panel or meter box [up to your utility] wire size is #4 stranded bare copper. because this is a replacement, not a new install, you can get by without installing arc-fault breakers. arc-fault breakers go for about $39.00 each.

[LazyPup]

but the post says the existing wire is 14/2 and that is connected to 20A breakers???

Correct me if I am wrong, but its my understanding that 20A requires AWG 12 ,,AWG 14 is limited to 15A

[HayZee518]

yeah, you are correct. 14 gauge wire needs a 15 amp breaker - 12 gauge needs a 20 amp. if you find that downstream of a 12 gauge circuit someone placed a 14 gauge wire, then you need to reduce the breaker to a 15 amp or replace the whole run with a 12 ga cable. there is no place for inter-mixed cables.

[Wolfeie]

Thanks for the tips so far. Let's keep this going so I get it right the first time.

Preface: Got it about the FPE panel. Will not replace with the same and I am familiar with the trial and tribulations of FPE breakers (regardless of the fact that they lost and then regained their UL listing...)

1. Understood that if the individual house circuits have 14 ga wire then 15A, NOT 20A breakers. If they turn out to be 12 ga then 20A. No problem.

2. Regarding the new 50A circuits (3). The appliance manual states the wiring requirement as 3-50A circuits with 8ga wire. Please see the table in the attachment to this post - I am installing the Steibel Tempra 29 Plus tankless electric water heater. Do I go with the 8 or 6ga?

3. Outstanding question remains about the conduit run. Can I run the wires for all 3 circuits in a single conduit? If so, what size is needed for 7 wires or 8 or 6 ga? (Each circuit is a 2 pole, and one ground)

4. Regarding the "ground loop". I take it that this means that I use the braided CU and connect the TWO ground stakes together and then to the panel. Right?

5. Got it about the cost and wire size difference between the AL vs CU.

Thanks again for your help and I feel that I'm getting close.
[IMG]file:///C:/DOCUME%7E1/ADMINI%7E1/LOCALS%7E1/Temp/moz-screenshot.png[/IMG]

[HayZee518]

Service entrance

thanks for the tips so far. Let's keep this going so i get it right the first time.

Preface: Got it about the fpe panel. Will not replace with the same and i am familiar with the trial and tribulations of fpe breakers (regardless of the fact that they lost and then regained their ul listing...)

1. Understood that if the individual house circuits have 14 ga wire then 15a, not 20a breakers. If they turn out to be 12 ga then 20a. No problem.

2. Regarding the new 50a circuits (3). The appliance manual states the wiring requirement as 3-50a circuits with 8ga wire. Please see the table in the attachment to this post - i am installing the steibel tempra 29 plus tankless electric water heater. Do i go with the 8 or 6ga?


3. Outstanding question remains about the conduit run. Can i run the wires for all 3 circuits in a single conduit? If so, what size is needed for 7 wires or 8 or 6 ga? (each circuit is a 2 pole, and one ground)

4. Regarding the "ground loop". I take it that this means that i use the braided cu and connect the two ground stakes together and then to the panel. Right?


5. Got it about the cost and wire size difference between the al vs cu.

Thanks again for your help and i feel that i'm getting close.
[img]file:///c:/docume%7e1/admini%7e1/locals%7e1/temp/moz-screenshot.png[/img]

unless someone re-wrote the amperage tables, #8 was always rated for 40 amp. Go with #6 - 65 amps.

When more that three conductors are run in any conduit, their amperage rating is de-rated by a percentage. Up to 3 - 100%. 4-6 i think its 80% i'll have to look at the book, the ground is not considered a current carrying conductor. For seven wires at 80% fill, 1 1/4 inch is needed.

Use stranded #4 bare copper. Start at the panelbox, go out to the first rod, then to the second rod, then back to the panelbox and terminate at the neutral busbar. The neutral is bonded to the enclosure by means of a supplied screw or bonding jumper.