Condenser's High Pressure Switch Keeps Tripping.
#1
Member
Thread Starter
Join Date: Jun 2018
Location: United States
Posts: 2
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Condenser's High Pressure Switch Keeps Tripping.
Hi All, Hope you're having a great day, or night. I'm a Jack of all trades, master of none.
I'm trying to figure out, what I should do next. Writing here to see if anyone may possibly
be able to diagnose the problem with my Heat Pump, according to the symptoms I describe. I run it 24/7 365 days a year, heat or cool,(one or the other). The system is about 18 years old. Throughout those years, the only thing I've had to do to it, is replace the condenser motor about four times and that's it, they just burn out. Actually, I had replaced the motor last summer because it burned out. I've been running it on cool since spring, about 4 months now. Even though we had a snow about two months ago. I've been having problems with it for about two weeks now. I would notice that it wasn't cooling, I would go outside and the condenser motor would be stopped. I would press the high pressure reset button, and it would come back on. Even though it seemed odd that it would burn out in one year, I just went ahead and purchased a new motor and motor run capacitor, and replaced them. I had a feeling, I was destroying a good motor, when I cut the shaft, to remove the fan without damage, but I didn't have a fan puller and that was just the quickest way to get the job done. The thing is, it's still tripping the high pressure switch. Up until yesterday, it was tripping it between 4:00 and 5:00pm, just once a day. Seemed like around the hottest part of the day. But today, I've had to reset it 4 times already. One of those times, the middle one, when I pressed the button nothing happened. I pressed it several more times, and nothing. I went back inside and about an hour later, I noticed it had started up all by itself. The last time it tripped today, it started right up, when I pressed it. It's not an over-charged condition because it's never been serviced by any technician, since install. The highest outdoor temperature so far these days, has been around 95, but usually around 90. It's never been cleaned, but I've looked through the fins and it has very little debris, but I'm going to clean it anyways probably in the next couple of days. The only other thing I can think of is a faulty high pressure switch, but I wouldn't know how to test it, or if there even is a way to test it. Although I can say, that about four times in the recent past, when I tried to press the button, nothing happened. I don't know if that means the high pressure switch is bad, or if that is normal. Please, If anyone can shed some light on, and help me with this problem, I would really appreciate it. Thank You
I'm trying to figure out, what I should do next. Writing here to see if anyone may possibly
be able to diagnose the problem with my Heat Pump, according to the symptoms I describe. I run it 24/7 365 days a year, heat or cool,(one or the other). The system is about 18 years old. Throughout those years, the only thing I've had to do to it, is replace the condenser motor about four times and that's it, they just burn out. Actually, I had replaced the motor last summer because it burned out. I've been running it on cool since spring, about 4 months now. Even though we had a snow about two months ago. I've been having problems with it for about two weeks now. I would notice that it wasn't cooling, I would go outside and the condenser motor would be stopped. I would press the high pressure reset button, and it would come back on. Even though it seemed odd that it would burn out in one year, I just went ahead and purchased a new motor and motor run capacitor, and replaced them. I had a feeling, I was destroying a good motor, when I cut the shaft, to remove the fan without damage, but I didn't have a fan puller and that was just the quickest way to get the job done. The thing is, it's still tripping the high pressure switch. Up until yesterday, it was tripping it between 4:00 and 5:00pm, just once a day. Seemed like around the hottest part of the day. But today, I've had to reset it 4 times already. One of those times, the middle one, when I pressed the button nothing happened. I pressed it several more times, and nothing. I went back inside and about an hour later, I noticed it had started up all by itself. The last time it tripped today, it started right up, when I pressed it. It's not an over-charged condition because it's never been serviced by any technician, since install. The highest outdoor temperature so far these days, has been around 95, but usually around 90. It's never been cleaned, but I've looked through the fins and it has very little debris, but I'm going to clean it anyways probably in the next couple of days. The only other thing I can think of is a faulty high pressure switch, but I wouldn't know how to test it, or if there even is a way to test it. Although I can say, that about four times in the recent past, when I tried to press the button, nothing happened. I don't know if that means the high pressure switch is bad, or if that is normal. Please, If anyone can shed some light on, and help me with this problem, I would really appreciate it. Thank You
#2
You need to have someone put gauges on the high pressure side and determine at what pressure the switch shut off (opens). Then try to determine if the condenser fan motor randomly shuts off or does the high pressure control need replaced. 4 condenser fan motors is a lot of replacements. Do you know the running amperage of the fan motor. If the running amperage is close to or exceeds the amperage on the nameplate, I would replace it with the next larger size motor. hope this helps.
#3
Member
Thread Starter
Join Date: Jun 2018
Location: United States
Posts: 2
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Thank You for your input Steamboy.
I was wondering if regular auto A/C gauges would work on a heat pump, (300psi & Fitment).
Because I need to change the compressor on my auto's A/C and instead of paying the $600 that
they want, I will buy the gauges, Vacuum pump and replacement Compressor, for around $250, and
will still have the tools left over afterward. If those same gauges will work on the heat pump,
I might as well order them now, because a technician isn't going to sit around waiting for the
switch to trip, for possibly over an hour in the 90-100 degree heat, which causes the trip to occur. (but now it even trips in the middle of the night) The motor specs: usmotors.com, Model#K55HXCLP-1470, HP 1/4-1/8, VOLT 208-230, HZ 60, AMP 2.0, PH 1, RPM 825. Something strange happened yesterday, one of the times that I reset the HP switch, I pressed it and the compressor came on (as usual), but the motor didn't start. (realize this is a brand new motor) About 30 seconds later, the motor kicked on. That has only happened once. I did replace the contactor a couple of years ago. Right now, I'm left keeping an eye/ear on the condenser unit and going outside and resetting the switch every time it cuts off.
I was wondering if regular auto A/C gauges would work on a heat pump, (300psi & Fitment).
Because I need to change the compressor on my auto's A/C and instead of paying the $600 that
they want, I will buy the gauges, Vacuum pump and replacement Compressor, for around $250, and
will still have the tools left over afterward. If those same gauges will work on the heat pump,
I might as well order them now, because a technician isn't going to sit around waiting for the
switch to trip, for possibly over an hour in the 90-100 degree heat, which causes the trip to occur. (but now it even trips in the middle of the night) The motor specs: usmotors.com, Model#K55HXCLP-1470, HP 1/4-1/8, VOLT 208-230, HZ 60, AMP 2.0, PH 1, RPM 825. Something strange happened yesterday, one of the times that I reset the HP switch, I pressed it and the compressor came on (as usual), but the motor didn't start. (realize this is a brand new motor) About 30 seconds later, the motor kicked on. That has only happened once. I did replace the contactor a couple of years ago. Right now, I'm left keeping an eye/ear on the condenser unit and going outside and resetting the switch every time it cuts off.
#4
Member
A few years ago I had a similar problem and it turned out to be the high pressure switch - specifically where the wire is connected right at the switch .
It was a broken wire which was connected most of the time but intermittently would open. The way I discovered it was to put an analogue ohm meter across the contacts (removed from control board) and jiggle the wires .
While it's improbable that this is your issue, it's a reminder that sometimes it's the switch / wiring so it's a good idea to check the switch circuit, wires, contacts etc.
It was a broken wire which was connected most of the time but intermittently would open. The way I discovered it was to put an analogue ohm meter across the contacts (removed from control board) and jiggle the wires .
While it's improbable that this is your issue, it's a reminder that sometimes it's the switch / wiring so it's a good idea to check the switch circuit, wires, contacts etc.
#5
Member
Thread Starter
Join Date: Jun 2018
Location: United States
Posts: 2
Upvotes: 0
Received 0 Upvotes
on
0 Posts
This morning, (6/21/18) I had a HVAC company come out. (I finally got tired of constantly going out and resetting that switch.) You can see the grass starting to form a trail, from my walk back and forth to the condenser unit. Anyways, the guy put his gauges, and some other test equipment on the unit, unplugged, re-plugged wires, he even checked the inside unit, (it was clean). He could not find anything wrong with it! He said, "everything is working as it should". Even though the coils are not really dirty, there is a little grass debris here and there, I asked him, if I should clean them? He said, "It wouldn't hurt". I asked him, if I should try jumping the High Pressure switch? He said, "He wouldn't recommend it, because something is causing it to trip". He was here about a half hour, Charged me $80, to come out. I guess that's fair, But basically he did absolutely nothing. I'm exactly right where I started. Yesterday I reset the switch at least (8) times, even though I was out for about 5 hours. He said, to call if it happens again. I'm 100% sure, It's going to happen again, Guaranteed. What am I supposed to do? This is ridiculous. If anyone could possibly help, "Please", I would really appreciate it, Thank You.
Last edited by Gushwa; 06-21-18 at 08:27 AM.
#6
Member
either the shutoff is due to real high pressure or bogus signal - some thoughts for troubleshooting:
- did you measure the pressure when the event occurs and know for sure that it is a high pressure fault ? - maybe persuade the technician to leave a gauge attached or buy one if it's difficult to capture the pressure. … see suggestion of steamboy above
-did you measure the resistance at the switch leads to confirm its shorted when okay, open when declaring a fault ? how difficult is it to replace the switch ?
- where is the reset button ? integral with switch ? on a control board ? or ?
- did you measure the pressure when the event occurs and know for sure that it is a high pressure fault ? - maybe persuade the technician to leave a gauge attached or buy one if it's difficult to capture the pressure. … see suggestion of steamboy above
-did you measure the resistance at the switch leads to confirm its shorted when okay, open when declaring a fault ? how difficult is it to replace the switch ?
- where is the reset button ? integral with switch ? on a control board ? or ?
#7
One thing you can check without guages is the temperature of the liquid line leaving the condensing unit.
When operating normally the temperature of the liquid line should be about 100 degF.
If you were to feel the liquid line which is the smaller one after the unit has been running awhile 100 degF would be not noticeable.
If the line is very warm or hot your high pressure trip out could be from the condensing unit overheating from either a dirty condenser, bad fan motor or an improperly installed or wrong fan blade.
If it trips out and the line is not hot the tripping could be from a problem with the sealed system or bad control.
When operating normally the temperature of the liquid line should be about 100 degF.
If you were to feel the liquid line which is the smaller one after the unit has been running awhile 100 degF would be not noticeable.
If the line is very warm or hot your high pressure trip out could be from the condensing unit overheating from either a dirty condenser, bad fan motor or an improperly installed or wrong fan blade.
If it trips out and the line is not hot the tripping could be from a problem with the sealed system or bad control.
#8
It sounds like a faulty defrost control or you put in a motor with a lower FLA rating than the original.
What does the heat pump nomenclature list for motor FLA?
Since you are in cool mode this season, an easy test would be to take the black fan motor off of the defrost control and connect it the the contactor terminal that feeds the defrost control.
If you post a picture of your control wiring we may be able to offer better assistance.
Do you have a make and model number?
It would be the 2 black wires at OF1 and OF2 on the defrost control in this Carrier example...
It would be the 2 black wires on FAN of the defrost control of this Lennox example...
It would be the 2 black wires at COM and N.C. on the defrost control in this Trane example...
What does the heat pump nomenclature list for motor FLA?
Since you are in cool mode this season, an easy test would be to take the black fan motor off of the defrost control and connect it the the contactor terminal that feeds the defrost control.
If you post a picture of your control wiring we may be able to offer better assistance.
Do you have a make and model number?
It would be the 2 black wires at OF1 and OF2 on the defrost control in this Carrier example...
It would be the 2 black wires on FAN of the defrost control of this Lennox example...
It would be the 2 black wires at COM and N.C. on the defrost control in this Trane example...