MEP-803A wiring into the home

[jaxbill]

I think I've read just about every thread for how folks have wired their MEP-803A into their home. Lots of good threads but found some differing opinions. Two questions come to mind...

1 -

It seems some wire for 50 A and others for slightly above to get the full capacity out of the MEP, which puts you into 60 A connectors. I believe I can use a 50 A back feed breaker w/interlock, all 50 A connectors, call it day, and be safe because of the lower breaker rating. However, the MEP could output more current if not for that breaker.

I believe the cheapest way to get a 60 A inlet, receptacle, plug, and cord connector is SCAME's Hubbell compatible (pin & sleeve) stuff and that's still about $475 in connectors. ElecDirect seems to be the main source for this. Is that right or is there something more cost effective?

FWIW - Beyond the extra capacity, I do see some value in IP67 watertight gear but not sure it's worth an extra $150-$200.

2 -

For me, since I need to reach 75-100', I think my SOOW wiring choice will be the same whether I put 50 A or 60 A connectors/plugs on the cord.

The way I read this chart is that two current carrying 6 AWG conductors are only rated for 45 A at the extended distance, presumably due to voltage drop. But, I can't tell if that amperage is calculated at the cord rated voltage of 600 A.

If the cord rated voltage is irrelevant, then I am stuck buying a cord with 4 AWG conductors but I at least get a 55 A rating.

Does anyone know for sure? I think I found the NEC code for this and could not find anything about lower ampacity over 50' distances.

I've even seen some cable re-sellers list the 6/4 SOOW as 45 A max. Like these guys: http://www.sjoow.com/soow/6-4-soow-600-volt.html

SOOW Ampacity

6 AWG, 55 A @ <50ft, 45 A >50ft

4 AWG, 70 A @ <50ft, 55 A >50ft


https://www.stayonline.com/reference-circuit-ampacity.aspx

 

[Daybreak]

Howdy,

Generator connection choices

Besides looking at SOOW cord, you can look at Type W also.

4 wire 8 AWG type W is listed at 65 amps

 

[jaxbill]

Howdy,

Generator connection choices

Besides looking at SOOW cord, you can look at Type W also.

4 wire 8 AWG type W is listed at 65 amps

Thanks for the reminder about type W. I don't recall why I got focused on SOOW. I need to go back and compare. A quick check says that type W will save me quite a bit of money and about 26 less pounds to carry around.

 

[stugpanzer]

Thanks for the reminder about type W. I don't recall why I got focused on SOOW. I need to go back and compare. A quick check says that type W will save me quite a bit of money and about 26 less pounds to carry around.

I have about the same run (75~100') and wasn't aware of Type W. How can 8 gauge wire carry more than the soow 6 gauge? Does it have to do with how many actual copper conductors in the Type W versus the SOOW?

 

[stugpanzer]

Google is my friend!

http://www.wesbellwireandcable.com/SOOW/difference-between-soow-wire-and-type-w-power-cable.html

For those that are familiar with Type W, how does the flexibility compare to SOOW?

 

[jaxbill]

Google is my friend!

http://www.wesbellwireandcable.com/SOOW/difference-between-soow-wire-and-type-w-power-cable.html

For those that are familiar with Type W, how does the flexibility compare to SOOW?

I found a supplier who referenced type W for devices not requiring a ground and I moved on. I think they were referring to a 2 conductor option but it was worded so explicitly I just skipped past it.

I feel like I am missing some negative aspect of type W. It's cheaper, lighter, more durable, and can carry more current than SOOW. Why would someone buy SOOW, ever?

 

[stugpanzer]

I found a supplier who referenced type W for devices not requiring a ground and I moved on. I think they were referring to a 2 conductor option but it was worded so explicitly I just skipped past it.

I feel like I am missing some negative aspect of type W. It's cheaper, lighter, more durable, and can carry more current than SOOW. Why would someone buy SOOW, ever?

I found this: https://www.wireandcableyourway.com/8-awg-4c-type-w-portable-power-cable.html

And this: http://www.wesbellwireandcable.com/PowerCable/8-4-w-multiconductor-industrial-power-cable-81314.html

Moderators...if I am violating for posting those links, please advise and I will revise my post.

 

[jaxbill]

I'll keep looking into the possible negatives on Type W. I did read something where I inferred the strands are finer but that's okay so long as the connectors are rated for fine stranded conductors. I suppose this could make installation a bit more difficult (for the non-professional).

 

[jaxbill]

For anyone else looking at the SCAME pin and sleeve 60 A connectors, it looks like it is only rated for 4 or 6 AWG conductors. It says S, SO, SOW, G or W wires only. I read SOW was replaced by SOOW. I will ask the reseller tomorrow to confirm SOOW is in fact even supported.

 

[Chainbreaker]

As far as interlock kits goes I used this mfg's kit and it was reasonably priced and very good quality: https://natramelec.com/

I really like Hubbell connectors, well built and easy to wire. I have found some GREAT deals on eBay for Hubbell products. Just do a search and LOTS of them will come up.

 

[Daybreak]

Howdy,

I am not sure where you were pricing type W cord. It's not cheap. SOOW cord is cheap compared type W.

Type W is very flexible. The outer covering is tough.

 

[stugpanzer]

Howdy,

I am not sure where you were pricing type W cord. It's not cheap. SOOW cord is cheap compared type W.

Type W is very flexible. The outer covering is tough.

Do you have suggestions for where to get Type W? From what I am seeing for a 100' run the Type W 8/4 cord seems like a better way to go than 6/4 SOOW as the ampacity of the 8/4 Type W is 65 amps whereas (it seems) when you get past the 50' mark in the 6/4 SOOW cord it drops to 45 amps.

 

[jaxbill]

Howdy,

I am not sure where you were pricing type W cord. It's not cheap. SOOW cord is cheap compared type W.

Type W is very flexible. The outer covering is tough.

I was comparing 4/4 SOOW to 8/4 type W to get the same ampacity at 100'. That's probably not the right comparison and that's why the price looked better. From what I have read on supplier's websites, I would need to increase the wiring gauge on the Type W for runs over 50'. i.e. the rated ampacity is only valid for runs less than 50'.

 

[stugpanzer]

I was comparing 4/4 SOOW to 8/4 type W to get the same ampacity at 100'. That's probably not the right comparison and that's why the price looked better. From what I have read on supplier's websites, I would need to increase the wiring gauge on the Type W for runs over 50'. i.e. the rated ampacity is only valid for runs less than 50'.

The only Type W Ampacity chart I can find is this: http://www.cmewire.com/catalog/sec17-mnc/mnc-01-amp.pdf

It shows 8/4 to have ampacity of 54 amps but does not give any distances.

 

[jaxbill]

Do you have suggestions for where to get Type W? From what I am seeing for a 100' run the Type W 8/4 cord seems like a better way to go than 6/4 SOOW as the ampacity of the 8/4 Type W is 65 amps whereas (it seems) when you get past the 50' mark in the 6/4 SOOW cord it drops to 45 amps.

I haven't gotten too far looking at price so far. Wire/Cable your way is where I was comparing things. SJOOW had a better price for SOOW so I assume Type W can also be had for a better price elsewhere too.

I read a supplier's site last night that basically said for all portable cable types you should increase the gauge when you go over 50'. What I can't find is an ampacity table (like we have for SOOW) for Type W. Nor can I find the NEC code that discusses the impact on cord length at all. The folks on Mike Holt's forum said it won't be in the code and you have to figure it out for each job but I'm not exactly sure how you do that.

I'm going to talk with an electrician before I order anything. I just wanted to be somewhat knowledgeable before I did that.

 

[stugpanzer]

I haven't gotten too far looking at price so far. Wire/Cable your way is where I was comparing things. SJOOW had a better price for SOOW so I assume Type W can also be had for a better price elsewhere too.

I read a supplier's site last night that basically said for all portable cable types you should increase the gauge when you go over 50'. What I can't find is an ampacity table (like we have for SOOW) for Type W. Nor can I find the NEC code that discusses the impact on cord length at all. The folks on Mike Holt's forum said it won't be in the code and you have to figure it out for each job but I'm not exactly sure how you do that.

I'm going to talk with an electrician before I order anything. I just wanted to be somewhat knowledgeable before I did that.

I too will not buy until I have done my homework which is why I am very interested in this thread!

 

[Daybreak]

Howdy,
Any SOOW or Type W cord is meant for temporary power usage. That is also why you want flexible cord. If you have a run over 50ft, you should really be looking to a hardwire solution. Running underground conduit, with THHN wire of size. Conduit large enough to support the 4 wires as well.

Say you have a light post 100ft from your house, and you use a 100ft extension cord....

Southwire Type W listing

Southwire Type W cord specs

 

[DieselAddict]

As wires get longer the voltage drop becomes the dominant factor in conductor sizing. If you want to use a 100' cord between the generator and the connection point you should choose your conductor size per the voltage drop table for the conductors you are considering. Under 50' ampacity is the dominant factor in sizing the conductors. If the voltage drop is high enough (meaning the total resistance of the wire) it can have negative impacts to motor loads such as your AC/HP compressor and your fridge/freezer compressors.

Based on one of the posts above - You COULD choose to use say 100' of #8 Type W and be in spec on current capacity but you will be way outside the normal 5% voltage drop. Even using #6 you are over the voltage drop if you draw the full capacity of the generator.

But Hey, I can boost the voltage at the generator right? Yes and No. You can bump it up a little and stay closer to spec at the point of use BUT your voltage will swing more between high and low load conditions. Its not the end of the world necessarily but not something you should design for if you can help it. Your lights will flicker more which can be annoying.

I chose to use #6 SOOW cord because it is what was readily available and I also use the cord with a spider box in other applications. I do not load my setup even close to the max unless I'm trying to test things so voltage drop is not so bad. That was my choice but I acknowledge it wasn't the best choice. If I were to do it again I would go with #4 type W.

 

[stugpanzer]

I just got off the phone with a technical support person from General Cable and as was said by DieselAddict it is the voltage drop. He gave me specs on Type W 8 AWG cord. He was using 4 conductor as an example (with all 4 carrying current) and that cord is rated at 65 amps. For 8/4 single phase 240 (2 legs of 120, a neutral and a ground) would be a 7.31 voltage drop at 100 feet so from 120 volts down to 112.69 volts (just over a 6% drop) so it seems (to me) that it is a viable option for 100' or less especially for temporary use. My actual length I need is 75' which is a voltage drop of about 5 volts per leg so about 115 volts (about a 4.2% drop)....still very usable.

He also stated that the Type W is rated for much higher operating temperatures which is why the smaller gauges can handle more current/amperage than SOOW.

 

[Farmitall]

I just got off the phone with a technical support person from General Cable and as was said by DieselAddict it is the voltage drop. He gave me specs on Type W 8 AWG cord. He was using 4 conductor as an example (with all 4 carrying current) and that cord is rated at 65 amps. For 8/4 single phase 240 (2 legs of 120, a neutral and a ground) would be a 7.31 voltage drop at 100 feet so from 120 volts down to 112.69 volts (just over a 6% drop) so it seems (to me) that it is a viable option for 100' or less especially for temporary use. My actual length I need is 75' which is a voltage drop of about 5 volts per leg so about 115 volts (about a 4.2% drop)....still very usable.

He also stated that the Type W is rated for much higher operating temperatures which is why the smaller gauges can handle more current/amperage than SOOW.

That's a 5v drop under no load conditions. Once you put a load on that line, you will see an additional drop as current begins to flow.

Current and voltage are ALWAYS inversely proportional, meaning as current rises, voltage drops and vice versa.

Motors of any type will not like it if it goes too low. A motor cannot tell if it is being under voltage or physically over loaded torque wise, the result is the same which is excessive current draw and the production of heat.....sometimes lots of it and if it stalls, it will burn up.

If you cheap out on the main feed, you are just begging for problems further down the line. It would be hard to justify the "savings" buying a smaller conductor cable and then having an expensive repair bill on a heating system or other appliance.