Trailer Life Magazine Open Roads Forum: Shore works ATS in and out on Gen power
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class A Motorhomes

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Shore works ATS in and out on Gen power

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next
Sponsored By:
enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 08/18/19 08:28am Link  |  Quote  |  Print  |  Notify Moderator

The genset neutral must be grounded between the genset and transfer switch. So, yes connect white wire to ground bar.
Loose connections normally only need to be tightened. I would take each one complete loose one at a time. If the wire and connection point are of different metals, apply some good qulity de-oxidation grease. Then reinstall and tighten securly.


Bud
USAF Retired
Pace Arrow

2003 Chev Ice Road Tracker


dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 08/18/19 08:45am Link  |  Quote  |  Print  |  Notify Moderator

1. A 7.5 Genset will NOT have 240 between the 2 hot leads. EACH lead will have the 120 when connected to either Ground or WHITE(Neutral). below 10k Gensets are sane phase.
2. The NEUTRAL from both the Shore AND the Genset is NOT- Grounded. The Neutral goes from the Genset to the ATS Neutral connection on BOTH sources. The Neutral on the ATS for the Genset input bus/connection. The Neutral from Shore to the ATS shore Input bus/connection.
3. Usually. clicking in and out indicates momentary voltage loss. Especially if you have replaced the ATS for the same problem. Doug

enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 08/18/19 09:34am Link  |  Quote  |  Print  |  Notify Moderator

It is a violation of the NEC to ground the neutral and shore power in the rig. Shore power is only grounded at the service connection point. The genset must have the neutral bonded to ground.

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 08/18/19 10:38am Link  |  Quote  |  Print  |  Notify Moderator

enblethen wrote:

It is a violation of the NEC to ground the neutral and shore power in the rig. Shore power is only grounded at the service connection point. The genset must have the neutral bonded to ground.


Really. I have worked on motorhomes and Gensets for 40 years. The 120 pigtail coming OUT of a Genset for 50 amp and above Gensets. Has 4 to 5 wires.
2 wires are the Black HOT output
1 or 2 wires(depending on the Genset) are WHITE Neutral wires
then 1 wire is the ground output.
ALL go straight to the ATS or the 50 amp female receptacle(if no ATS system). At no point is the Neutral grounded. The Neutral wire goes straight to the inside 50 amp breaker panel from the ATS system to the Neutral BUSS Bar. The GROUND goes straight to the GROUND on the Inside Breaker BUSS bar. At no time are the Ground and Neutral connected. I am NOT an expert on the NEC or how it relates to RV systems. ALL I KNOW, is, HOW 120 systems are connected and used in RV's. ALL RV's have a separate Neutral BUSS Bar and a GROUND BUSS bar.
Last, ATS systems do NOT look for true 50 amp out of phase HOT to operate. 50 amp EMS systems do. Doug

enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 08/18/19 10:48am Link  |  Quote  |  Print  |  Notify Moderator

OP is dealing with a Generac Guardian 7.5. It is not the same set up as other gensets including Onan. Generac Guardian series are commonly used as standby power systems for homes and small businesses.
NEC 250-34(B) and (C) in my old code book makes it clear that the system conductor that is reuired to be grounded shall be bonded to the genset frame.
I have worked on gensets and power systems for nearly 50 years

DrewE

Vermont

Senior Member

Joined: 08/23/2014

View Profile


Offline
Posted: 08/18/19 11:50am Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

enblethen wrote:

It is a violation of the NEC to ground the neutral and shore power in the rig. Shore power is only grounded at the service connection point. The genset must have the neutral bonded to ground.


Really. I have worked on motorhomes and Gensets for 40 years. The 120 pigtail coming OUT of a Genset for 50 amp and above Gensets. Has 4 to 5 wires.
2 wires are the Black HOT output
1 or 2 wires(depending on the Genset) are WHITE Neutral wires
then 1 wire is the ground output.
ALL go straight to the ATS or the 50 amp female receptacle(if no ATS system). At no point is the Neutral grounded...


On my RV (and I think it's typical of most proper installations), the neutral and ground are bonded together inside the genset. Both connect to the genset's chassis; in my case, to a little vaguely crown shaped bit of metal that attaches where the main genset chassis ground tie attaches to the genset. If measured with an ohmmeter, the neutral and the ground lines coming out from the genset should show a short.

It is true that they should not be connected together at any time for the shore power cord, which is the main reason the transfer switch must switch the neutral as well as the hot(s).





dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Offline
Posted: 08/18/19 01:42pm Link  |  Quote  |  Print  |  Notify Moderator

DrewE wrote:

dougrainer wrote:

enblethen wrote:

It is a violation of the NEC to ground the neutral and shore power in the rig. Shore power is only grounded at the service connection point. The genset must have the neutral bonded to ground.


Really. I have worked on motorhomes and Gensets for 40 years. The 120 pigtail coming OUT of a Genset for 50 amp and above Gensets. Has 4 to 5 wires.
2 wires are the Black HOT output
1 or 2 wires(depending on the Genset) are WHITE Neutral wires
then 1 wire is the ground output.
ALL go straight to the ATS or the 50 amp female receptacle(if no ATS system). At no point is the Neutral grounded...


On my RV (and I think it's typical of most proper installations), the neutral and ground are bonded together inside the genset. Both connect to the genset's chassis; in my case, to a little vaguely crown shaped bit of metal that attaches where the main genset chassis ground tie attaches to the genset. If measured with an ohmmeter, the neutral and the ground lines coming out from the genset should show a short.

It is true that they should not be connected together at any time for the shore power cord, which is the main reason the transfer switch must switch the neutral as well as the hot(s).


I am talking AFTER the Power source. NOT internal of a Genset. From the discussion, it was making it sound like the connections NOT from the Internal wiring of the Genset, but at the ATS and interior Breaker Box, you combine the Neutral and Ground. You do NOT do that. Doug

enblethen

Moses Lake, WA

Senior Member

Joined: 01/05/2005

View Profile






Posted: 08/18/19 05:30pm Link  |  Quote  |  Print  |  Notify Moderator

It has to be before the transfer switch on the genset feeder.
It cannot be in the 120/240 volt distribution panel.

garry1p

Oklahoma

Senior Member

Joined: 08/12/2004

View Profile



Good Sam RV Club Member

Offline
Posted: 08/18/19 05:48pm Link  |  Quote  |  Print  |  Notify Moderator

I think you are saying the same thing no bonding at the distribution panel.

Best answer to the question is dropping voltage from the generator.

Could be a loose wire but my guess is slip rings need cleaning from setting up.

Might try turning circuit breakers off at the generator and let it run for a while then flip breakers back on with no load.


Garry1p


1990 Holiday Rambler Aluma Lite XL
454 on P-30 Chassis
1999 Jeep Cherokee sport


Juddla

South

New Member

Joined: 08/17/2019

View Profile


Offline
Posted: 08/18/19 05:57pm Link  |  Quote  |  Print  |  Notify Moderator

All-
ATS- progressive dynamics pd52. 240 amp relay switch is new.

I’ve checked at junction box. That’s out of genset where wires from gen meet wires that travel direct to ATS.
FROM GENSET I HAVE: 1 green,1 blk, 1red, and 2 wht. Wht are tied to large whit headed towards switch. Black on blk. Grn on copper and red to red.
120 at both red and blk here.

Now from ATS I have 120ish at red and 120ish at blk then that’s click of switch showed multimeter drop to 60 then builds to 240 btwn both and switch activate again. Then cuts out - Constant back and forth.
No load during this time.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Shore works ATS in and out on Gen power
Search:   Advanced Search

Search only in Class A Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:

© 2019 CWI, Inc. © 2019 Good Sam Enterprises, LLC. All Rights Reserved. | Terms of Use | PRIVACY POLICY | YOUR PRIVACY RIGHTS