Results 1 to 8 of 8
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13-09-2019, 12:57 PM #1
Copeland ZRD-81 noise issue during modulation
Hi,
I have a problem with compressor ZRD81. AC unit is equipped with one compressor and during PWM modulation, when pressure LP and HP are almost same - appears strange noise (check link below):
https://drive.google.com/file/d/18Nh...ew?usp=sharing
Any ideas what is going on?
Thanks
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20-09-2019, 03:43 PM #2
Re: Copeland ZRD-81 noise issue during modulation
Can't get the audio to work, maybe there is not enough pressure differential to hold the scrolls together as designed at low load. The digital scrolls (not sure if that what you have) do growl a bit when unloading and loading.
Mostly found in Oxfordshire, UK :)
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21-09-2019, 08:10 PM #3
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22-09-2019, 04:51 PM #4
Re: Copeland ZRD-81 noise issue during modulation
compressor running the wrong way ?
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23-09-2019, 05:23 AM #5
Re: Copeland ZRD-81 noise issue during modulation
Some times just before pressure equalized, scroll is turning backwards .
To avoid it' a NRV should be installed on the discharge line.
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23-09-2019, 05:36 AM #6
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Re: Copeland ZRD-81 noise issue during modulation
Hi
Most scrolls has this chek valve
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23-09-2019, 08:18 PM #7
Re: Copeland ZRD-81 noise issue during modulation
sounds like gas pulsing through a valve
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07-10-2019, 10:35 AM #8
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Re: Copeland ZRD-81 noise issue during modulation
Probably mechanically damaged compressor!
Check this thread on another forum:
https://hvac-talk.com/vbb/showthread.php?2194688-Copeland-scroll-rattling-noise-every-10-15-seconds