Goodman 2.5 50 foot run, pulsing on discharge line

[mooka]

Hi all new to the forum.

I belive I have posted this else where and no response. I installed a Goodman 2.5 ton unit, with the furnace 50 feet from the condenser. Installation went well, charged to factory specs, called goodman to verify the amount of r22 to go into a 50 ft line set. The lines are 3/4, 3/8. Started the unit after a good deep vacume, let it pull for an hour. Charged with the amount, started the unit and it cools fine. Now the pulsing problem. The suction line, right at the evap coil "pulses" It sort of jumps. It started pretty steady, no knowing what to do and the customer asking is that normal, i added a bit more 22. The pulsing slowed. Using my superheat/cool guage(a fieldpiece, not a plug for them just what I use to do my superheats/cools) all was okay there. So I added a bit more r22 and the pulsing slows even more, now just a random bump every couple mins or so. Could it be I have a ball of silfoss in where the dischage goes into the evap coil? I have never done such a long run of copper before, furnace was on the driveway side, so could not put condenser on that side of house. Any thoughts on what I should do next? This was last june I installed, it worked fine, hense the pulsing till september. Live in northern Canada, so residential units only run at max 5 months out of the year. I have the info on how much r22 I put in at the customers house, my record keeping seems to stay much better that way. Is there something I am over looking or is this a bigger problem?
Thanks
Tim

[tinknocker service tech]

pressures high and low
what are the gauges doing at the time of pulse
superheat
subcool
out side temp
inside temp
td accross the coil
air flow cfm calculated
static pressure supply return
amp draw of compressor and blower
voltage reading of unit


with out any of this cant say for sure

sounds like noncondensable to me but only a guess

[Shophound]

Is this "pulsing" you're speaking of on the liquid line feeding the metering device? Is it a piston/flow rater metering device or a TXV? What were your pressures, saturated temps, superheat and subcooling running at when you noticed these pulses?

Off the cuff, "pulsing" in the liquid line can mean flash gas...the liquid in the liquid line is experiencing pockets of the liquid flashing off into vapor due to either being heated (such as a liquid line in a hot attic) or a long length of undersized liquid line, creating a pressure drop.

[marlboroman]

The questions the other 2 posters asked are very important... If you could provide that info, you will find your answer to the problem your having...

Did you ask goodman if that 50ft run of copper was properly size with 3/4 -3/8 copper?

[mooka]

pressures high and low
what are the gauges doing at the time of pulse
superheat
subcool
out side temp
inside temp
td accross the coil
air flow cfm calculated
static pressure supply return
amp draw of compressor and blower
voltage reading of unit


with out any of this cant say for sure

sounds like noncondensable to me but only a guess



This is all going to be rechecked come spring/summer, just looking for anyone who has run into this or has an idea off the top of the head.
Thanks, and will post the results of these tests when I get to the unit, weather permiting.

Tim

[mooka]

The questions the other 2 posters asked are very important... If you could provide that info, you will find your answer to the problem your having...

Did you ask goodman if that 50ft run of copper was properly size with 3/4 -3/8 copper?

Yes, I let them know that. They said it was fine.
Tim

[I_bend_metal]

Doesn't all of this qualify as DIY???

[mooka]

Is this "pulsing" you're speaking of on the liquid line feeding the metering device? Is it a piston/flow rater metering device or a TXV? What were your pressures, saturated temps, superheat and subcooling running at when you noticed these pulses?

Off the cuff, "pulsing" in the liquid line can mean flash gas...the liquid in the liquid line is experiencing pockets of the liquid flashing off into vapor due to either being heated (such as a liquid line in a hot attic) or a long length of undersized liquid line, creating a pressure drop.

Its a cap tube metering device, no TXV. Stated in the other replys, will get this info again when I can get back to customers house. I have though myself the pressure drop, but using rated size tubing, according to goodman it should be okay. The line is in the basement, thats going to be my first trial, insulating the discharge line part way, mabye it is flashing along the way.

Tim

[RoBoTeq]

Sorry mooka, but your use of HVAC terminology doesn't sound like you're a pro to me. If you have a fixed metering device (no, you do not have a cap tube metered unit because Goodman never used cap tubes for metering.) then the only thing I can think of that would create pulsing is contaminates in the system.

Leaving a vacuum pump on for an hour is a useless measure of whether it evacuated the system. In fact, it could just as well have pulled moisture into the system if there was a leak somewhere during evacuation.

Despite all of the attempts to sound like a pro, there is not one useful bit of information in any of your posts.

[mooka]

Sorry mooka, but your use of HVAC terminology doesn't sound like you're a pro to me. If you have a fixed metering device (no, you do not have a cap tube metered unit because Goodman never used cap tubes for metering.) then the only thing I can think of that would create pulsing is contaminates in the system.

Leaving a vacuum pump on for an hour is a useless measure of whether it evacuated the system. In fact, it could just as well have pulled moisture into the system if there was a leak somewhere during evacuation.

Despite all of the attempts to sound like a pro, there is not one useful bit of information in any of your posts.

I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
Tim

[tinknocker service tech]

I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
Tim



you pulled it down to 100 microns in an hour:confused:
then you filled it with nitro> I hope you pulled it back down before you let the refrigerant into the system. If not then there is a very good chance you will need to let the smoke out before you replace he compressor

[pecmsg]

I had not said I was a pro, apprentice, trying to get get ready for the summer time rush. I held the vaccum at 100 microns, while the pump was off to help prove no leaks. The Nitrogen was after. I am sorry my my attempts for help make me sound like an attempt to be a pro, thanks to the others on here that gave me valuable tips on where to check next.
Tim

Its tough to fool a RoBoTeq!

[docholiday]

Me thinks a hold of 100 microns for an hour is nearly impossible. (Your hoses leak more than that).

[teeball57]

I used to have pump overnite to get to 350 microns. This new equipment is simply amazing!