RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > RV Systems & Appliances
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 10-31-2020, 08:55 AM   #1
Member
 
Holiday Rambler Owners Club
Join Date: Apr 2020
Location: Farmington Hills, Michigan
Posts: 43
Buzzing noise from Transfer Switch when hooked to shore power

Can anyone tell what a pretty loud buzzing noise is on my transfer switch when hooked up to 50A shore power, did it just get bad? This is the first time I've heard that noise. It is at my home 50A outlet I've used numerous times this fall. My phone records on MP4 and I can't upload the file here.
The unit is "Elkhart Automatic Transfer Switch - 50 Amp Service - Es50m-65n" on a 2004 HR Imperial.
To my knowledge there is nothing electrical hooked up but my Progressive Industries EMS is showing like 6 amps on L1, 0 amps on L2. Flipped all the circuit breakers off and on that I could find, but no change on the noise.
Both the house and chassis batteries are around 13.1V.
It did get to the 30s yesterday but I don't think there is any kind of heater hooked up anywhere that I can find.
__________________
2004 Holiday Rambler Imperial 40PKD
Lowflyer1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-31-2020, 09:10 AM   #2
Community Administrator
 
Spk64's Avatar


 
Newmar Owners Club
Join Date: Apr 2014
Location: Southern Indiana
Posts: 14,289
It can be somewhat normal depending on type of transfer switch.
But loose connections can also make it worse. It is best to check the connections inside the transfer switch annually.
__________________
Steve
2002 Newmar Mountain Aire 4095

Wash your Hands, Wear a Mask, Social Distance
Spk64 is online now   Reply With Quote
Old 10-31-2020, 09:14 AM   #3
Senior Member


 
Join Date: Aug 2017
Location: Burien, Wa
Posts: 274
Lowflyer,
It could be dust on the contacts. They. Can be cleaned with some compressed air. Remove shore and generator when doing so.
I had the same unit in our 04 Intrigue and the buzzing got worse over time and could not rectify by cleaning so I installed a DC contact relay ESCO LPT50BRD coach is like a library now, never been this quiet
Good luck and let us know what you find out,
Greg
__________________
Greg and Vicki R.
2004 Country Coach Intrigue "Sweet Serenade"
40' Quad slide CCI #11811
gnvrvin is online now   Reply With Quote
Old 10-31-2020, 09:21 AM   #4
Senior Member
 
Triangle Drifter's Avatar
 
Join Date: Jan 2007
Location: Bermuda Islands
Posts: 709
Nothing likes to be hit. A slap on the wall directly outside of the switch stopped it for awhile but eventually you have to get inside & tighten down all of the connections.
__________________
Home: Bermuda
US RV base, MD
2007 Alpenlite 34RLR
Triangle Drifter is offline   Reply With Quote
Old 10-31-2020, 09:43 AM   #5
Senior Member
 
Ljwt330's Avatar
 
Join Date: Jan 2018
Location: Capistrano Beach, California
Posts: 2,390
Agree with all posts, typical transfer switch issue. Remedies suggested should be tried. Older units tend to get noisier with age. Not a safety or proper function issue, just a nuisance. Replacement with a DC powered contact switch will solve the problem if you can't live with it.
__________________
Larry, Eileen, and Finley
2004 Alpine 36FDDS
Third motor home, first Alpine, no need for another.
Ljwt330 is offline   Reply With Quote
Old 10-31-2020, 10:54 AM   #6
Member
 
Holiday Rambler Owners Club
Join Date: Apr 2020
Location: Farmington Hills, Michigan
Posts: 43
Thank you all for a quick response. I checked all the connections and they were tight. Just to be sure the connections are clean, I backed them all out and re-tightened. No Help. The current on L1 actually varies and sometimes shows 10 or 11 amps and that does not make sense but worries me where is it going.

Couple of good bangs on the contactors and the noise stopped and current went to 0 amps. But maybe 30 sec later the noise is back and current back to like 11 amps. Tried that couple times with same results.
Since there appears to be a circuit board and a smaller box below also, I probably need a new transfer switch, not just a contactor?
I was hoping to find an identical unit so I can swap without any extra mounting or wiring effort.
Is there anything close to my current unit or would the ESCO LPT50BRD be a simple swap? The pics on line are blurry but look like the connections are quite a bit different.
Attached Thumbnails
Click image for larger version

Name:	20201031_104548.jpg
Views:	7
Size:	221.3 KB
ID:	306547  
Attached Images
 
__________________
2004 Holiday Rambler Imperial 40PKD
Lowflyer1 is offline   Reply With Quote
Old 11-01-2020, 07:03 AM   #7
Senior Member
 
veraken's Avatar


 
Monaco Owners Club
Vintage RV Owners Club
Holiday Rambler Owners Club
Join Date: Jul 2012
Location: Lexington, SC
Posts: 1,991
The unit you have is similar to the ESCO ES50M-65N. The major difference between the two transfer switches is The LPT50BRD is a Relay Base unit that is much quieter. The ES50M-65N has Mechanical Contacts that make a hum when running.

https://www.pplmotorhomes.com/parts/...atic_ES50M-65N

https://www.pplmotorhomes.com/parts/...-50amp_49-1749
__________________
Vera & Ken
1998 Holiday Rambler Imperial, RR8S Chassis
Cummins 6C8.3 mechanical engine, 325HP, 3060 Allison
Towing 2014 Ford Explorer
veraken is offline   Reply With Quote
Old 11-01-2020, 07:12 AM   #8
Senior Member
 
Old Scout's Avatar
 
Join Date: Nov 2005
Posts: 6,155
...2x on the DC contactor model, Lyght/Esco is a very good product -- no issues.
__________________
Old Scout
2003 Alpine 40' MDTS
New Braunfels, Texas
Old Scout is offline   Reply With Quote
Old 11-01-2020, 07:31 AM   #9
Senior Member
 
Join Date: Jul 2014
Posts: 24,632
10 or 11 amps could be the block heater if you have a diesel.
twinboat is offline   Reply With Quote
Old 11-01-2020, 08:25 AM   #10
Member
 
Holiday Rambler Owners Club
Join Date: Apr 2020
Location: Farmington Hills, Michigan
Posts: 43
Thank you all for the feedback.
I did not even think about unplugging the block heater the second time around as I only unplugged it the fist time when I was trying to figure out the noise. So that's probably the current draw. Now the bus is back in storage and I can't work on it until next weekend earliest and depending Michigan weather, might be next spring.
One comment I saw on Amazon for Esco LPT50BRD: "While it is rated for 50A I don't like that it is wired with #10 wire. My 50A power cord uses #6 wire to the RV receptacle. #6 wire from receptacle to transfer switch and #6 wire from transfer switch to circuit breaker panel. My last transfer switch failed when the #10 internal wires over heated and melted into the ground...."
Is that a concern or did they have some other problems?
Also, there were comments that there were no installation instructions. I've done relay swaps in the past but those have been identical units and just follow pin to pin. Due to the real confined space (my unit is in behind the water heater), there is not much room to do anything.
Are the diagrams clear enough on the Esco LPT50BRD to follow from the old ES50M-65N?
__________________
2004 Holiday Rambler Imperial 40PKD
Lowflyer1 is offline   Reply With Quote
Old 11-01-2020, 08:55 AM   #11
Senior Member
 
docj's Avatar
 
Join Date: May 2011
Posts: 6,940
Last year my Esco ES50M-65N developed an internal short that prevented me from using shore power. I decided to replace with an identical unit to avoid having to make wiring changes. Getting to mine requires that you crawl into the "basement" and the working space is very limited. Total time to replace was less than an hour.

The new one came from with a note that "this device could make some noise" but I don't hear any, particularly with it tucked away underneath. My original switch lasted ~19 years; if I get anywhere close to that with this one I'll be happy.
__________________
Joel Weiss--Campground Reviews administrator
RV Technology Specialist
2000 40' Beaver Patriot Thunder Princeton CAT C-12
docj is offline   Reply With Quote
Old 11-01-2020, 10:26 AM   #12
Senior Member
 
Ljwt330's Avatar
 
Join Date: Jan 2018
Location: Capistrano Beach, California
Posts: 2,390
Quote:
Originally Posted by Lowflyer1 View Post
Thank you all for the feedback.
I did not even think about unplugging the block heater the second time around as I only unplugged it the fist time when I was trying to figure out the noise. So that's probably the current draw. Now the bus is back in storage and I can't work on it until next weekend earliest and depending Michigan weather, might be next spring.
One comment I saw on Amazon for Esco LPT50BRD: "While it is rated for 50A I don't like that it is wired with #10 wire. My 50A power cord uses #6 wire to the RV receptacle. #6 wire from receptacle to transfer switch and #6 wire from transfer switch to circuit breaker panel. My last transfer switch failed when the #10 internal wires over heated and melted into the ground...."
Is that a concern or did they have some other problems?
Also, there were comments that there were no installation instructions. I've done relay swaps in the past but those have been identical units and just follow pin to pin. Due to the real confined space (my unit is in behind the water heater), there is not much room to do anything.
Are the diagrams clear enough on the Esco LPT50BRD to follow from the old ES50M-65N?
I believe the #10 wiring is for the DC relays and does not carry the loads to/from shore power or generator. Why the poster's wires failed is unknown, but loose connection at the relays could account for his wiring meltdown.
__________________
Larry, Eileen, and Finley
2004 Alpine 36FDDS
Third motor home, first Alpine, no need for another.
Ljwt330 is offline   Reply With Quote
Old 11-01-2020, 10:43 AM   #13
Senior Member
 
Join Date: Jul 2014
Posts: 24,632
Quote:
Originally Posted by Ljwt330 View Post
I believe the #10 wiring is for the DC relays and does not carry the loads to/from shore power or generator. Why the poster's wires failed is unknown, but loose connection at the relays could account for his wiring meltdown.
They may be able to use individual 10 gauge wire, on the short jumpers, inside the ATS inclosure.

Amp rating is based on the type of wire or cable.
twinboat is offline   Reply With Quote
Old 11-01-2020, 11:11 AM   #14
Senior Member
 
Piros1's Avatar
 
Join Date: Dec 2015
Location: Dittmer, MO 63023
Posts: 653
In my experience working in the field the relay contractors in the transfer switch are similar to what we used in the sign and lighting industry. Typically the hum is created by the magnetic coil that pulls the contractor open or closed depending on type. Generally when this happens the coil is getting weak or there is something obstructing the contractor from opening or closing completely. It can still work but eventually like most everything will fail. If I were in your shoes I would consider replacement. I have seen contractors fail in months and then some last 20 years or more. But quality units aren’t cheap.
__________________
2005 CC Affinity 770, 2006 Jeep TJ
2015 Newmar Essex 4553
Piros1 is offline   Reply With Quote
Reply

Tags
noise, power, shore power, switch, transfer switch



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
No DC power with shore power hooked up. Migkiller Monaco Owner's Forum 19 03-01-2019 07:13 PM
Automatic transfer switch loud buzzing keeps us awake! mcaimh Monaco Owner's Forum 11 07-25-2017 01:45 PM
Noticeable Buzzing from Power Inverter When Plugged in to Shore Power seanp iRV2.com General Discussion 4 04-23-2017 10:24 AM
Buzzing Noise from Transfer Box porchdog2 5th Wheel Discussion 9 07-23-2016 12:31 AM
no power unless hooked to shore power ken551 Winnebago Industries Owner's Forum 7 06-21-2012 06:55 PM


All times are GMT -6. The time now is 01:45 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.