digital scroll

[nando]

Hello,

Digital Scroll: Copeland HLR31 - when the temp. has reached, the compressor don't stop at low pressure (pump down), he stays working in his own capacity regulation.
Anybody an idea?

[cadwaladr]

what does the suction guage read,have you attached service gauges?

[THE DUDE]

Im not shure what application you are using it for. The Digital Control works off a Demand Signal of 1-5 VDC. The Compressor Capacity is @ 100% @ 5VDC and unloading between 1.3-5 VDC. The Compressor will shut off when the Demand Signal drops below 1.25 VDC. It will restart when the Demand Signal rises over 1.44 VDC and the Anti short cycle timer ( if applicable) times out. You may have somthing wired incorrectl. The Pressure swithes sould be in the M1-M2 circut.

[nando]

Thanks for the replay,
One coolroom with two evaporators, one aggregate with one digital en one normal compressor.
***** R507, SET = 2.8 bar ( - 15°C ), When the temp. has reached, the compressor stops about 2 bar, after a little bit, the pressure increases about 2.5 bar, the digital compressor starts and stay running around the SET point and not stop anymore (or after 10 min. or so).
The min. run time is 0 sec.
The low pressure setting is now 2 bar, but Copeland Holland advises 1 bar, but with this setting he sure don't stop.
The wirering is made at Copeland self, I have to bring only the power supply (and the connection condensor).

[wineman]

on a digital scroll the condensing unit is controlled on pressure which is related to the cabinet temp your lp switch is for safety alll depends on what application you are using it on and what refrigerant you have in your system your digital scroll is only putting hot gas back in to your suction to keep the suction pressure up so it isnt over to big for the application its designed for if only part load is required