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tamar120 04-10-2010 08:13 PM

Vending machine problem
alright, first off nice to see there's a forum like this, i'm a HVAC trainee in trade school. anyways I was taking a look at a vending machine, original complaint was that the condenser fan motor wouldn't come on, I replaced the current relay and the condenser fan came on and ran and the compressor as well, as far as i knew, problem solved. Well I get a call back saying the evaporator coil was frozen solid, I pulled out the evaporator to find 2 bad evaporator motors, replaced and rewired now, i forgot to mention the first time i tried to wire it i had it wrong and it shorted out and tripped the breaker all 3 motors run but the compressor tries to come on every 10 or 15 seconds but doesn't, it's I'm thinking I either burned up the start capacitor or it's wired wrong it's rated current is like 6.00 amps, I put my amp meter on it only to find it's drawing like 0.10 - 0.15 amps when trying to start, you can hear the compressor give a little poot as it tries to start. I checked the compressor to ground and it's not grounded. What do you guys think? Appreciate all the answers and opinions. by the way, here's a link to compressor data

tamar120 04-11-2010 09:16 AM

Coke vending machine problem, hvac techs take a look
bump? :(

DangerMouse 04-11-2010 09:35 AM

I moved this to Appliances where you'll likely get a speedier response. Not an HVAC question.
The doctors will be in shortly to assist you.


Jacques 04-12-2010 05:47 AM

this is basically just a standard refrigerator. if you opened it up and found comp hot and off on overload-cool it down[wait or use a fan]when it resets does fan then come on ? [some are wired in series with overload].if not then cond fan bad. if it clicks right back off-use a 3n1 to direct test comp[first check windings for ground or open] if won't start on direct test-comp bad. if does start but amp draw is high-comp bad..don't know why your amp reading is so low sounds like start winding not in ckt but you would then hear a slight hum and not a 'poot'. possible you have a blown cap or evap mtrs wired in series? and now not enough power to comp.?

tamar120 04-12-2010 10:59 PM

still not sure
wel all the fan motors are all good(they are running), now as far as the wiring i'm not sure. it's like the relay clicks in every 10 or 15 seconds trying to put voltage to the start winding of the compressor (i'm hoping) and when it does the compressor moves you can actually hear it compress one time but it draws low amps and does not start... i'm thinking bout putting a hard start on there permanently but i'm still not sure what i need to do

what would make a compressor do that?

Jacques 04-13-2010 06:48 AM

the 3n1[sized to comp HP] will act as a hard start. don't use them on anything other than older single phase comp w/o run caps. if won't start with a 3n1-the comp bad. if you change it; you're aware you need to be certified...good to keep one in your truck as a test should sign up on pro sites for better info and help. most of us are old now but like to help young guys coming up.

tamar120 04-13-2010 03:05 PM

i appreciate it im going to go out there thursday and put the 3-n-1 on there.. im just hoping i been living right and the compressor isnt gone bad, before all this happened she was running fine the suction line was getting cold, the evaporator turned into a block of ice (the fans were not running) so i think im good as far as leaks.. you think a miswired relay would make it do that?

also i did check the comp with the ohm meter, everything seemed to check out good, continuity to all the terminal, also it was not grounded

Jacques 04-14-2010 07:10 AM

could have. maybe the start winding is burned, so you still read through it but it's no good. would need a megger to be sure.. find out Thur.. was wondering if they sold you the right relay for this unit. if it is a burn out ask your instructor what he/she suggests. on a warranty call everything would get replaced[due to oil contamination] .in any event don't get discouraged; this stuff happens, you learn from it and go on. it gets easier and easier. great trade, always feed your family.

tamar120 04-16-2010 09:25 PM

i put the 3-n-1 on there, everything started and worked fine. Now apparently the evaporator is freezing up. im thinking maybe the two fan motors on the evap are pulling the wrong way.. air is supposed to be pulled thru the evaporator coil right?

Jacques 04-19-2010 10:01 AM

glad to hear no s/s prob.. you may have put blades on backwards. when you look at a fan mtr of this type[what's the part # ?],check the pole wrapped around stator at top,that determines direction, replacement should match. on the universial type you can take them apart to reverse direction. i would only use them if you're stuck-too much hassel sometimes-better to use oem. you're probably better off, on this small stuff, going to an appliance parts store. on HVAC or bigger units go to refrigeration supply store. don't be reluctant to ask Q's, if they know you're breaking into trade they'll be glad to help-usually.. get a couple of different catalogs,they'll help you learn the parts and what fits what.

tamar120 04-19-2010 12:06 PM

what a relief
im glad to say i finally figured it out and its running good now, all it was was the temperature sensing part of the thermostat was not in a very good place, i just pretty much shoved it in the evaporator coil, the reason it was freezing up is because the compressor never cycled off, now she cycles right off when the temperarture gets too cool, thanks for all your help

DangerMouse 04-19-2010 12:31 PM

See? I knew you'd get the help you needed here.
Glad it worked out.


7up VF154 04-21-2012 07:11 PM

7up soda machine compressor issue
I bought a soda machine for my basement a few months ago and it was working great. I noticed it was getting warmer and warmer after a couple of months. The valve to charge it with refrigerant was slightly opened. I recharge it the other day with an R12 replacement. After I charged it the compressor would not turn off at all but the machine was cold again. I figured it was still low on refrigerant so I added more R134 to the system. Now the compressor tries to cycle but doesn't stay on. I talked to my appliance repair neighbor and he said it could be moisture in the system. I also checkrf online and the system may be charged too much. The compressor is very noisey when it runs too. Any suggestions?

DangerMouse 04-22-2012 06:19 AM

7up VF154: My suggestion would be to post your question in a new thread of it's own so people can see it! :)


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