No power when hooked up to shore

[Water Dog]

There is one more thing I would do before pulling the old relay out. I would disconnect the control wires to the relay and the generator side. Only leave the output side and shore power side hooked up and then plug in shore power and see if you have power. It would be very very remote, but possible that you could have some dc voltage backfeeding that relay to hold it to the generator side. It would be a good idea to rule that out before buying parts.

I have a story about throwing $900 worth of parts at a generator only to find out the problem was the converter allowing trace AC voltage through and keeping relays on the generator circuit board latched.

 

[Just Lou]

The relay (switch) is only activated when the generator is running.  (You've proven that part works).  The relay is completely deactivated during shore power use,.  The shore power is passed through on the normally closed contacts of the de-activated relay.  I'm guessing the contacts have pitted and simply do not make contact when closed, to allow the shore voltage to pass.  Remove all power and inspect, and burnish (clean) the contacts.

You might also try to de-activate the time delay circuitry within the switch.  As water-dog stated, something may be keeping the switch activated.

 

[rgnprof]

OK guys, thanks a lot for the ideas!  I am new to all of this and have learned a lot in the past several months.  Let me run one more observation by you - when I took the cover plate off of the switch I am looking at a wiring connector compartment - a small area that actually sits above the switch.  The switch is below another piece of metal and kind of hard to get a good look at.  In this 'wiring connector' compartment (basically, a junction box), all of the wires are connected with wire connectors and their is a diagram that has Line on one side and Generator on the other and someone, presumably the dealer wrote a #1 beside the Line and a #2 beside the Generator - and, the Romex leading into the box are numbered - with a pen - 1 and 2 as well.  So, I'm thinking that wire #1 is coming from the shore and #2 is coming from the generator.  Make sense, right?  BUT, the numbers don't match!  According to my voltage readings, the wire labeled #1 is actually coming from the Generator, while the #2 wire is coming from the shore connection.

Is is possible that this thing has been wired 'backwards' from the dealer??  Would it matter?

I haven't pulled the switch all the way out yet - was just trying to figure out as much as I could before doing that.

Ryan

 

[Just Lou]

Is is possible that this thing has been wired 'backwards' from the dealer??  Would it matter?

I haven't pulled the switch all the way out yet - was just trying to figure out as much as I could before doing that.

Ryan

It's certainly possible.  The symptoms would be as you've described, if the relay is dead. 

Can you open it enough to see the small switch that defeats the 15-30 second delay?  That may allow it to pick.

 

[Water Dog]

You should be able to check your voltage at the wire nutted connections to find your shore power leg. Hopefully the relay has a set of terminals marked "NC" (normally closed) that should be the side that your shore power connects to. The other should be marked "NO" ( or normally open) that would be the terminals that the generator would be wired to. There might be a second wire coming off the Generator side that goes either through a time delay and a rectifier, or to a circuit board with those items on it then returns to the control terminal on the relay.

Just noticed:
You said in your first post, that it HAD been working fine. If that was the case, then it is probably not wired in reverse (or if it is then the control or latching wire would have to have been from the shore power side as well), or it would have been just as dead when you initially plugged it in.

 

[Just Lou]

[quote author=Water Dog ]
Just noticed:
You said in your first post, that it HAD been working fine. If that was the case, then it is probably not wired in reverse, or it would have been just as dead when you initially plugged it in.
[/quote]

Dennis, I was going to write the same thing in my last post, but it's not so.  If the relay used to pick, then it would appear to work normally unless someone specifically tried to check which source had priority. 

Few of us would notice the delay when attaching shore power. 

The only thing that would really change is that if you started the generator with the shore power connected, the gen would never feed the panel.

 

[Water Dog]

Dennis, I was going to write the same thing in my last post, but it's not so.  If the relay used to pick, then it would appear to work normally unless someone specifically tried to check which source had priority. 

Few of us would notice the delay when attaching shore power. 

The only thing that would really change is that if you started the generator with the shore power connected, the gen would never feed the panel.

I think I see what you're saying Lou, but there would have to be power being supplied to the coil in the relay coming from somewhere and the only place with power would be shore power at that point. So I can see what you are saying is true as long as the time delay etc is also being fed by shore power. ..... unless I'm completely missing the point - which by the way wouldn't be the first time. Anyway I found a little drawing that might help the OP with his diagnosis.

http://www.rvparts.com/itemNotes/schematics/Iota/Transfer%20Switches/151-ITS30R_Wiring.pdf

 

[Just Lou]

I think I see what you're saying Lou, but there would have to be power being supplied to the coil in the relay coming from somewhere and the only place with power would be shore power at that point. So I can see what you are saying is true as long as the time delay etc is also being fed by shore power.

You got it Dennis.

 

[rgnprof]

Ok, we are in the middle of a blizzard here in Oklahoma City - so I pulled the old switch to try and test it.  I'm not sure how to test the coil for ohms...or what values are good, or bad?  Any advice?

Thanks, Ryan

 

[Water Dog]

Do you have the switch itself out or the whole "can" that the switch is housed in? If you have the switch out, do you also have the time delay board out, and is it still wired to the switch? If you have the switch only, just use an ohm meter or a continuity tester and see if there is continuity between both terminals on the power cord side (N.C.) to the opposite terminals on the panel side (COM) There should be no resistance with the switch in it's normal position. That was the side you were having problems with (unless you determined that it was wired backwards) You should be able to move the contacting lever up and down against spring pressure with your finger. I don't know what the resistance value should be on the coil, but if the whole thing was wired right, the coil shouldn't be energized for shore power anyway. If you still have the time delay control hooked up you could make a 110 pigtail and hook to the generator terminals (N.O.) then plug it in. That should energize the relay and you should be able to measure 110VAC across the COM terminals.

 

[rgnprof]

The switch/relay is actually riveted to the 'box' - I have the box out, so it is still a little hard to see everything.  But, I have confirmed that this thing was hooked up wrong - I guess from new.  The shore power line was definitely connected to what should have been the generator side of the relay.  It's pretty easy to follow the wires with the box off...The generator side of the relay is connected to the timer delay, which is not a board with an LED, but looks like another relay, of sorts.  I am still trying to figure out how this actually worked - being hooked up backwards...

The only online reference that I can find to testing the coil is from an Esco LPT30 switch - which according to the schematics looks just like the relay that is in my switch.  It says the resistance should be between 5500-6000 ohms.  Mine is testing at about 500 ohms.  At this point, I am replacing the switch - and hopefully will wire it up correctly.  I can't believe this was done wrong from the 'factory' - although I guess it is possible that this switch was replaced before.

ryan

 

[Just Lou]

The generator should be wired to the normally open contacts, but the timer (and the pick coil) should also be wired to these contacts.  The shore power should be wired to the normally closed contacts with no other wires.

 

[rgnprof]

It's fixed! I now have shore power, although I can't keep the generator running to actually test the switch (I think I'm low on gas, as the genny runs off the motorhome fuel tank).  I replaced the old switch with a new ATS 301 transfer switch from Parallax (easy installation), and I now have power.  Again, many thanks!

ryan

 

[scottydl]

Great!  Did you end up going with that same item linked earlier in the thread?  Just wondering in case mine ever acts up again, I probably will end up replacing it.

 

[Water Dog]

Always great to get something going again...good job, now you're a pro.

 

[rgnprof]

The pic on the Amazon link is actually of the older ATS 30 - I made sure to replace it with the ATS 301 (bought it off of Craigslist).

ryan

 

[scottydl]

Good to know... you must be near a major metropolitan area.  I always envy you folks who can actually find needed items on Craigslist.