Argo switching relay dead & but comes back it life. WHY?

Reply

  #1  
Old 10-24-14, 02:29 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
Argo switching relay dead & but comes back it life. WHY?

We have an Argo ARM 6P switching relay with three zones attached. Thermostat started acting up in the livingroom which seemed to be the start or our problem. The Argo relay acted dead so we replaced thermostat in the livingroom and Argo unit still totally dead. A few days later we turned power to the unit back on and it started. It will run the system for about an hour and will be dead again. Could it be the transformer in the unit which does feel warm?
 
Attached Images  

Last edited by Kellen65; 10-24-14 at 04:20 AM.
Sponsored Links
  #2  
Old 10-24-14, 04:58 AM
Member
Join Date: Jul 2009
Location: Toronto
Posts: 1,174
Upvotes: 0
Received 0 Votes on 0 Posts
Really hard one to answer.
It could be an overloaded transformer.
You would have to add up all the loads and see if the transformer has the capacity.
 
  #3  
Old 10-24-14, 05:05 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
We've had this system for seven years and have made no changes to what is hooked up to it. This just started doing this last weekend after a thermostat starting to not work properly.
 

Last edited by Kellen65; 10-24-14 at 05:39 AM.
  #4  
Old 10-24-14, 07:46 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
One of the features of the ARM panel is:

•Electronic Fuse - Auto reset
This is consistent with your description of the failure.

Electronic fuse is opening, after a time will reset.

If I had to guess, and I do, I would guess that there is a failed electrolytic capacitor on the control board.
 
  #5  
Old 10-24-14, 08:31 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
Is this a fixable or are we looking at a switching relay? I bought a new transformer to install to see if that is the problem.
 
  #6  
Old 10-24-14, 08:43 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
I don't think it's the transformer, the 'fuse' is after the transformer, so the problem is after the fuse, after the transformer.

I'm sure it's fixable... can you do it? I don't know... do you have experience troubleshooting and replacing components on PC boards?

It's also possible that something else is loading the circuit, that it's not one of the electrolytic capacitors.
 
  #7  
Old 10-24-14, 08:58 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
At the upper right corner of the panel there is a terminal strip with a red and white wire on it. Terminals are labeled COMMON and [email protected]

Where are those wires going?
 
  #8  
Old 10-24-14, 09:00 AM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
Thanks Trooper, yes I am familiar with PC boards. I can look for the bad/swollen part, at least we can direct our repair man to the issue, maybe we can get a less expensive repair than buy a new 200 switch.
 
  #9  
Old 10-24-14, 09:23 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
You may be answering my question about the red and white wires now... there may be a problem out at whatever they are powering also. They are 'robbing' power from the transformer and are downstream of the E-fuse.

It appears that there are four electrolytics on that board. Two of them are 'timing' capacitors for the priority circuit and I don't suspect that they are bad.

One is a 'filter capacitor' for the +15 VDC power supply to the IC chips. It's in parallel with a zener diode. If you're looking at the schematic in the ARM manual, it's near the bottom-ish, just above the two IC chips in the priority timer circuit.

I would suspect that the top would be bulged up some, and should be visible on close inspection, but another test would be if you can tell if the capacitor is noticably warmer when touching it. This would indicate that the cap is leaky and probably drawing excess current. Electrolytic caps should not be noticably warm when operating.

But before you get to that, tell me where those wires are going.
 
  #10  
Old 10-24-14, 01:30 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
Name:  image.jpg
Views: 2204
Size:  38.7 KBName:  image.jpg
Views: 2220
Size:  39.0 KBName:  image.jpg
Views: 2443
Size:  44.5 KBName:  image.jpg
Views: 2937
Size:  45.0 KB

The 2 common wires (red and white) lead to the bottom left to the "isolated switch". Red is capped, white is attached. Second white comes from a tekmar boiler control unit. No bulged electrolytics. There are 4 and the one to the very top left, right above the electronic fuse is warm to the touch, but just barely plus the top of the transformer is warm. The black section. So maybe the heat is coming from there.
 

Last edited by Kellen65; 10-24-14 at 01:59 PM.
  #11  
Old 10-24-14, 03:04 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Are there any markings on that so-called 'electronic fuse' ?

It could be just that component is bad... the so-called fuse. It looks like a PTC thermistor to me. I don't think it's actually a fuse at all. PTC means "Positive Temperature Coefficient".



A PTC device resistance goes UP when it gets warm, and of course goes down when it cools.

If that's what it is I suppose you could call it a 'fuse' of sorts. If too much current is drawn, it heats up and limits the current.

OK, so you've got a Taco controller also... it looks like there are two wires coming from the taco, one is wire nutted to the red, and the other is going to one of the X terminals.

What that is doing is powering the 'boiler demand' on the Taco from the 24VAC in the Argo. The X X endswitch is in series with that. When a zone calls for heat, it sends 24VAC to the Taco through that endswitch to signal a heat call to the Taco.

It's possible (but I don't think likely actually) that the Taco is drawing too much from the Argo transformer. You could test this by lifting one of the wires from one of the X X terminals and turn all the thermostats all the way up.

The boiler will NOT fire when you do this.

Wait and see if the Argo shuts down. At least this will tell you which direction you need to troubleshoot.

Did you say you have a multimeter? Do you know how to use it to measure AC current?
 
  #12  
Old 10-24-14, 03:10 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
That Tekmar control is for a four stages of boiler. This is a residence? You have a 'gas pump' too?

What boiler is that controlling? Only one boiler right?

Until I know more I'm going to say that controller is overkill.
 
  #13  
Old 10-24-14, 03:49 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
Name:  image.jpg
Views: 2364
Size:  44.5 KB

Things that nightmares are made of. We have a wood/coal burner. This whole system is set up with the understanding that when the boiler to the right runs out of wood or coal, when the water leaving that boiler goes down to 80 degrees, the gas boiler automatically starts.

Odd thing is, I turned the system on (not using the wood/coal yet) and it's been running fir three hrs with no problem.
 
  #14  
Old 10-25-14, 08:43 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
OK then... this adds a whole new layer of complexity, doesn't it?

What is the item to the left of the Argo that's connected to the Tekmar?

Do you really have a 'gas pump'?

Here's the bottom line:

SOMETHING is causing the so-called electronic fuse to cut out.

It could be that PTC fuse itself.

It still could be one of the electrolytic capacitors on the Argo board, most likely the one that is in parallel with the zener diode as seen in the schematic in the Argo manual. The fact that the one cap felt warm... and now that it's been running, it seems OK, could mean that the capacitor has 'reformed' itself and is no longer drawing too much current. If this is the case, it won't be long before it fails completely. There's a bit of information at this website about the how and why capacitors may fail and require reforming of the oxide layer on the plates:

Reforming Caps

It could be the Taco boiler demand drawing too much current. (skeptical of this though, it's only a relay coil being driven.

May be something else I haven't though of...

The symptoms do not indicate that the transformer in the Argo is bad.
 
  #15  
Old 10-26-14, 01:36 PM
Member
Thread Starter
Join Date: Oct 2014
Posts: 7
Upvotes: 0
Received 0 Votes on 0 Posts
The gray box to the left is what tells the boiler controls that the coal stove has reach a low enough temp that it is time for our gas boiler to kick on.

We have a gas boiler & no heat pump.

It ran today for five hours before it crashed. Only one zone running.

I'm giving the heating guy a call tomorrow.
 
  #16  
Old 10-26-14, 02:42 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
I'm giving the heating guy a call tomorrow.
Bummer...

You're going to end up with a big bill for a 39 cent part.
 
  #17  
Old 11-22-15, 07:13 PM
Member
Join Date: Nov 2015
Posts: 2
Upvotes: 0
Received 0 Votes on 0 Posts
I have met the similar issue for my arm-6p controller. When it fails i could push the lower right coner of the broad to bring ut to life. However admfter one or two hours it will die again. Such push to life capability seems become less effective as i did itbfor few days. Any clue to whatvthis might be?
 
  #18  
Old 11-22-15, 07:18 PM
Member
Join Date: Nov 2015
Posts: 2
Upvotes: 0
Received 0 Votes on 0 Posts
Angry

I have met the similar issue for my arm-6p controller. When it fails i could push the lower right coner of the broad to bring ut to life. However admfter one or two hours it will die again. Such push to life capability seems become less effective as i did itbfor few days. Any clue to whatvthis might be? Btw, after it run for a while (even with one zone on i can feel that transformer is warm, but at the same time no capacitor is noticeably warm )
 
  #19  
Old 11-22-15, 07:38 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Upvotes: 0
Received 1 Vote on 1 Post
Any clue to whatvthis might be?
Typical symptom of a bad solder connection on the PC board.
 
Reply

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


Thread Tools
Search this Thread
Display Modes