Generator Plug - Newbie Question


  #1  
Old 03-03-13, 05:01 AM
J
Member
Thread Starter
Join Date: Nov 2012
Location: USA
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
Generator Plug - Newbie Question

Hi I am a long time reader of the forum and appreciate all the wisdom and experience shared by the community.

My existing portable generator has one 20amp L14-20 4 prong twist outlet which connects to the house via a Reliance PB-20 inlet box, which in turn feeds a 30 amp breaker in the main panel controlled by an interlock. All was professionally installed by a licensed electrician. I am upgrading my generator to a unit which has a 30amp L14-30 4 prong twist outlet. I will replace the existing inlet box with a PB-30 and will of course replace the cord with One that had L14-30 plugs. My question is as follows-- I would like to keep the older unit as a backup. Is there any safety issue or electrical issue if I replace the female end of that cord with an L14-30 plug so that it will fit into the new PB-30 outlet should I need to use it?
 
  #2  
Old 03-03-13, 05:30 AM
S
Member
Join Date: Mar 2013
Location: USA
Posts: 70
Upvotes: 0
Received 0 Upvotes on 0 Posts
clarification

First, you're upgrading the generator from one that has a 20 amp 120 / 240 volt capacity to one that has a 30 amp 120 / 240 volt capacity, correct ?

Second, This means that all equipment in connection with this set up will need to be rated at 30 amps, the breaker in the panel ( under the lockout ), the 4 wire cord ends ( both male and female ), the extension cord ( # 10/4 SJ or other ) and the panel 30 amp generator inlet receptacle which is tied to the 30 amp breaker under the lockout mechanism next to the main breaker.

If you want to use the 20 amp rated generator as a back up, you'd have to change everything back as the 30 amp cord ends will not fit into the 20 amp 120 / 240 volt receptacle on the generator.

I'm sure I'm not understanding your question so with the above information, please clarify.
 
  #3  
Old 03-03-13, 05:42 AM
J
Member
Thread Starter
Join Date: Nov 2012
Location: USA
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
SoyBomb, in response to your reply--paragraph 1 -- you are correct. Paragraph 2 - I understand the entire system needs to and does support 30 amps. As to your third paragraph -- my question is -- can I just change the female end of the 4 prong cord on the old machine to connect to the new 30 amp inlet box which accepts a female L14-30 plug?
 
  #4  
Old 03-03-13, 06:33 AM
A
Member
Join Date: Aug 2010
Location: USA
Posts: 90
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes, you could do that, or you could sell the old cord and use this on the new cord:

PowerFit Outlet Adapter 20A 240-Volt To 30A 240-Volt-PF922033 at The Home Depot

Two questions, what is the wire guage between the inlet and the breaker box? Was that also upgraded?
 
  #5  
Old 03-03-13, 07:36 AM
S
Member
Join Date: Mar 2013
Location: USA
Posts: 70
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes you can as stated above. It's probably easiest to just have two cords made up so you won't have to mess with changing the ends around. One #12/4 wire with a 20 amp twist lock male and a 30 amp female. The other with a #10/4 wire with both a male and female 30 amp twist lock cord ends.
 
  #6  
Old 03-03-13, 08:31 AM
J
Member
Thread Starter
Join Date: Nov 2012
Location: USA
Posts: 12
Upvotes: 0
Received 0 Upvotes on 0 Posts
That is exactly my intent. Thanks
 
  #7  
Old 03-03-13, 08:45 AM
A
Member
Join Date: Aug 2010
Location: USA
Posts: 90
Upvotes: 0
Received 0 Upvotes on 0 Posts
Disreguard my post above. That L14-20 to 30 amp adapter probably wont fit your generator and at 12 bucks is more expensive than that L14-30 female connector that you are palnning to use on your other cord.
 
  #8  
Old 03-03-13, 08:46 AM
C
Member
Join Date: Jan 2013
Location: USA
Posts: 79
Upvotes: 0
Received 0 Upvotes on 0 Posts
Or instead of 2 separate cords you could make a short adapter for the new 10/4 cable using a 30 amp female plug for the end of your cord that normally would plug into the generator and a 20 amp male plug for the backup generator.

Since the backup will be a step down in amps there are no issues with your new 10/4 cable, but you will have to be careful to not overload the generator.

Something like this, only I couldn't find a ready made one with the plugs you'd need. Easy to make though on your own. L14-30p To L5-30r Power Cord Plug Adapter - product summary - Bing Shopping
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: