Help please... Dixie Narco DNBC 360/210-6 Surging Issue

[xgrover36x]

Hello -

Thought I'd give a shot at joining and posting here after reviewing many of the posts.  The community appears to be very knowledgeable and generous with your advice and I will allow you as many eyerolls as you need with me...  

So I bought a DNBC 360/210-6 for $100 sight unseen just because I wanted a garage free vend machine for beer & soda.  I've never owned a vending machine before, but I figured at that price, no big deal if it doesn't work.

It appears to be in great shape.  Powers up fine, seems to be cooling, fans are running, etc.  However, it "surges" every 15 seconds or so with the condenser getting loud, then quiet and the display lights flickering in time with the surge.  Any ideas what may be causing this issue?

Thanks!

[Gizmo Vending]

Could be anything.   What else is running on that particular circuit?   With nothing else running, then try the machine.  If you’re still having the same problem then disconnect the refrigeration system for a while and see if the surging stops.  If so you probably will have to wire in a new 3-1 starter to your compressor.  But before you do all that check all wires to make sure they aren’t frayed or chewed up by rats, etc. 

[AZVendor]

It sounds like the compressor turning off and back on which is short cycling.  That could be a bad thermostat, a bad compressor, a bad condenser fan, a clogged condenser, the machine shoved against the wall, etc.  In your garage I am surprised it isn't tripping a GFI on that circuit.

[xgrover36x]

8 hours ago, Gizmo Vending said:

Could be anything.   What else is running on that particular circuit?   With nothing else running, then try the machine.  If you’re still having the same problem then disconnect the refrigeration system for a while and see if the surging stops.  If so you probably will have to wire in a new 3-1 starter to your compressor.  But before you do all that check all wires to make sure they aren’t frayed or chewed up by rats, etc. 

Thanks for your reply.  Surging may be too strong of a word.  Notable cycling is probably more accurate.  All wires look to be in really good condition.  I think this machine has been indoors it's entire life by the looks of it.  I was curious if there was a reason why the display lights would be perfectly synced with the timing of the cycling in case that might be a clue to something. 

Did some additional testing last night.  Turned the thermostat cooler it didn't seem to have any change in the cycling.  Also, not sure if it is actually cooling because I don't really see any frost forming on the cooling grid fins after an hour or so.  All fans and lights and coin/bill acceptor seem to be working properly.

Also, 5 of the 6 selectors work to vend cans, so I'll need to do some troubleshooting on the one that isn't working.

[AZVendor]

Then you can try a 3 n 1 hardstart kit on the compressor.  If that doesn't work then it needs a new compressor.  The thermostat must be set at 3 1/2 from zero.

[xgrover36x]

6 hours ago, AZVendor said:

It sounds like the compressor turning off and back on which is short cycling.  That could be a bad thermostat, a bad compressor, a bad condenser fan, a clogged condenser, the machine shoved against the wall, etc.  In your garage I am surprised it isn't tripping a GFI on that circuit.

Thanks for your replys.  I provided additional information in my reply to Gizmo if that helps narrow things down.

I may have overstated the issue with the word "surging", but it does seem to be cycling the refrigeration components very frequently.  So maybe that's why it's not tripping the GFI?   I left it on for a little over an hour to see if maybe getting the temp cooler would at least make it less frequent.  As I stated in my other reply, I'm not sure it is cooling properly.

It is not against any wall currently during testing and all fans seem to be working well.  Any tests I could perform to eliminate the other potential problems you reference?

And are you referring to setting the thermostat @ 3.5 all the time regardless of installing a hard start kit?  I don't really see a marker on the thermostat to tell what number it's set to.

Thanks again!

[AZVendor]

Since it's not tripping the circuit breaker your power is probably fine.  The highest current draw is when the compressor is first starting and that isn't tripping it.  The thermostat is set at 3 1/2 and left there.  There is no need to ever adjust it.  Turn it all the way counterclockwise to off and that is zero.  Then turn it to where 3 1/2 would be based on that.  The capillary tube from the thermostat must be slid into a tube behind the evaporator and it's best if the cap tube doesn't contact other metal objects.  It's entirely possible that your thermostat is causing the hard starting so to rule that out, unplug the compressor from the machine at the lower left corner of the cabinet and plug it into an extension cord.  This bypasses the thermostat.  If the compressor still short cycles then it's bad.  If it no longer short cycles then your thermostat is causing it.

[xgrover36x]

On 11/23/2023 at 10:34 AM, AZVendor said:

Since it's not tripping the circuit breaker your power is probably fine.  The highest current draw is when the compressor is first starting and that isn't tripping it.  The thermostat is set at 3 1/2 and left there.  There is no need to ever adjust it.  Turn it all the way counterclockwise to off and that is zero.  Then turn it to where 3 1/2 would be based on that.  The capillary tube from the thermostat must be slid into a tube behind the evaporator and it's best if the cap tube doesn't contact other metal objects.  It's entirely possible that your thermostat is causing the hard starting so to rule that out, unplug the compressor from the machine at the lower left corner of the cabinet and plug it into an extension cord.  This bypasses the thermostat.  If the compressor still short cycles then it's bad.  If it no longer short cycles then your thermostat is causing it.

Update of further testing....

Set the thermostat to 3 1/2.  Unplugged the compressor and plugged in the machine.  Fans (evaporator?) still run constantly without "surging" and lights stay constant without "surging".  Unplug machine and just plug in compressor direct.  Compressor "surges" (hard cycles) as it did before.  Unplug compressor from direct power and plug it back into the machine port.  Plug machine back in.  No "surging" but...  Also no cooling.  I don't think the compressor is kicking on now because I left it plugged in for about an hour and there was no frost on coils or fins.  Does this information lead to a concrete diagnosis?  

Also...  The 5th soda compartment is full and the sold out trigger is depressed, but the sold out light is lit and it doesn't dispense cans.  1, 2, 3, 4, and 6 compartments all work fine.  Any suggestions on this issue?

Thanks again for all the great help!

 

[AZVendor]

You have a bad compressor and it needs to be replaced.  It sounds like column 5 is jammed.  That could be a bent rotor or a bad vend motor.

[xgrover36x]

14 minutes ago, AZVendor said:

You have a bad compressor and it needs to be replaced.  It sounds like column 5 is jammed.  That could be a bent rotor or a bad vend motor.

So I'm interpreting that it is beyond the cheaper fix of the 3n1 replacement then?  Can the compressor be replaced individually or is it better to replace the whole cooling deck?  Is there a good place to order these replacement parts?

- Thanks

[AZVendor]

You can still try a 3 n 1. You can get it at Grainger. Get one for a 1/3 hp compressor.

[xgrover36x]

7 hours ago, AZVendor said:

You can still try a 3 n 1. You can get it at Grainger. Get one for a 1/3 hp compressor.

Tried it again with direct power to the compressor and it isn't even trying to start now.  Not sure if it is clicking the start relay or not as the condenser fans are too loud.  Is this the correct part to try for the 3 n 1?   https://www.amazon.com/RCO410-Capacitor-Compatible-Refrigerators-Freezers/dp/B0B5MSV5F5/ref=sr_1_16?keywords=supco+3+in+1+hard+start+kit+for+refrigerators&sr=8-16

If so, it's cheap enough to give it a shot and see what happens

Thanks again!  The adventure continues...

Edited November 25, 2023 by xgrover36x

[AZVendor]

Yes

[xgrover36x]

Update...  I have taken out the old relay.  It rattled when I shook it so I'm assuming it was bad.  I installed the 3n1 per the included instructions.  Compressor starts and runs very smoothly and quietly.  However after about 15 minutes, the evaporator coils weren't very cold so I let it run for 45 more minutes.  Still no cooling happening.  Zero frost.  The  compressors continues to run smoothly the whole time.  It gets pretty warm on the housing and the copper tubes one gets warm but the other doesn't get cold.  Any clues as to what may need to be fixed?  And would it be something I could DIY?  I found a relay similar to the original (https://www.amazon.com/Combined-Protector-compressors-APSR-131C-Reference/dp/B01NAB4MSI/ref=sr_1_2?keywords=embraco+relay&sr=8-2) for about the same price as the 3n1.   Would using this make any difference or is it likely more related to refrigerant?

Thanks!!

[AZVendor]

It's low on freon.

[xgrover36x]

10 minutes ago, AZVendor said:

It's low on freon.

Is that something I could DIY?  And nothing to worry about with the housing getting hot?  Relay is not getting hot at all.

Thanks

[AZVendor]

The compressor bell housing is normally hot when it's running.  What relay are you asking about?  If it's the one in the door close to the coin mech then that has nothing to do with refrigeration - it's your credit relay.  Just leave the hard start kit on it until the compressor dies down the road. 

If you have a set of refrigeration gauges then you can recharge it.  But the thing is, you don't know what freon is in it.  If it's the original compressor and it's never been tapped with a Shraeder valve then it's probably R12 and you'd have to tap it to recharge it.  If it's been tapped then if the tap is on the short pigtail off the bellhousing then  it's not the original compressor or someone who repaired it did a good job by putting that valve on.  If you have a service saddle valve clamped onto the low side line somewhere then someone has previously recharged it.  If it's not the original compressor then it could have either R12, R134a or R401a (also called MP39) which is a blend that I always used because it drops in on top of R12 and R134a and can be it's own new freon charge.  The type of freon must match the oil that is in the bell housing - there are two kinds.

So, to sum up, if you don't know what you're doing you need to have a certified technician recharge it.

[xgrover36x]

2 hours ago, AZVendor said:

The compressor bell housing is normally hot when it's running.  What relay are you asking about?  If it's the one in the door close to the coin mech then that has nothing to do with refrigeration - it's your credit relay.  Just leave the hard start kit on it until the compressor dies down the road. 

If you have a set of refrigeration gauges then you can recharge it.  But the thing is, you don't know what freon is in it.  If it's the original compressor and it's never been tapped with a Shraeder valve then it's probably R12 and you'd have to tap it to recharge it.  If it's been tapped then if the tap is on the short pigtail off the bellhousing then  it's not the original compressor or someone who repaired it did a good job by putting that valve on.  If you have a service saddle valve clamped onto the low side line somewhere then someone has previously recharged it.  If it's not the original compressor then it could have either R12, R134a or R401a (also called MP39) which is a blend that I always used because it drops in on top of R12 and R134a and can be it's own new freon charge.  The type of freon must match the oil that is in the bell housing - there are two kinds.

So, to sum up, if you don't know what you're doing you need to have a certified technician recharge it.

Ha!  This response was awesome!  Have we met before?  It's like you can see into my soul... 

I was referring to the old start/run relay on the compressor.  Sounds like the 3n1 is good to leave in place.

And...  I don't really know what I'm doing with freon.  But also have no idea how to locate a technician.  Can I check with a local vending business maybe and see if they have anyone that would be able to do it on the side or is that frowned upon?

Thanks again...

[AZVendor]

If you're in a large city you can google vending machine repair.  You can also contact whatever local vending companies you have there and see who they use. 

[xgrover36x]

Update...  The factory tag near the condensor coils indicate R12 coolant.  There are no any Schrader valves or other ports on the any of the lines. I'm guessing it is the original compressor by the looks of it.  Does this make DIY less likely? If so, what would you expect a service tech to cost for a recharge? 

Thanks! 

[AZVendor]

If you have a set of gauges to use on it and you can find R12 and are capable of installing a line tap in the correct place.  A tech would be $100-150 I would think.

Edited December 2, 2023 by AZVendor

[xgrover36x]

On 12/2/2023 at 12:41 AM, AZVendor said:

If you have a set of gauges to use on it and you can find R12 and are capable of installing a line tap in the correct place.  A tech would be $100-150 I would think.

So would the tech be able to add new R12 or would they likely just add in the R134a or R401a? What would the cost of each be do you guess? 

[AZVendor]

Freon cost will vary. If they have R401a then you're fine. 

[Fermo Vending]

On 12/1/2023 at 12:16 PM, AZVendor said:

The compressor bell housing is normally hot when it's running.  What relay are you asking about?  If it's the one in the door close to the coin mech then that has nothing to do with refrigeration - it's your credit relay.  Just leave the hard start kit on it until the compressor dies down the road. 

If you have a set of refrigeration gauges then you can recharge it.  But the thing is, you don't know what freon is in it.  If it's the original compressor and it's never been tapped with a Shraeder valve then it's probably R12 and you'd have to tap it to recharge it.  If it's been tapped then if the tap is on the short pigtail off the bellhousing then  it's not the original compressor or someone who repaired it did a good job by putting that valve on.  If you have a service saddle valve clamped onto the low side line somewhere then someone has previously recharged it.  If it's not the original compressor then it could have either R12, R134a or R401a (also called MP39) which is a blend that I always used because it drops in on top of R12 and R134a and can be it's own new freon charge.  The type of freon must match the oil that is in the bell housing - there are two kinds.

So, to sum up, if you don't know what you're doing you need to have a certified technician recharge it.

@AZVendor MP39 is safe to blend with R-12 and & 134a? Worked for my father's HVAC company for a while and I don't think I ever knew that. 

[AZVendor]

Yes. That is all I used unless I encountered R404 or R22 or any other odd freon. It's a blend that mixes well with the two different oils that R12 and R134 compressors use.