10
5. CoMPRESSoR MANAGEMENt
compressor is allowed to operate depending on water temperature and room air temperature.
5.1. RooM AIR tEMPERAtURE
the compressor will stop when rt - hsPt > h28
the compressor can start when rt- hsPt < h27
HSPt
: room heating setpoint given by the room terminal
Rt
: room temperature measured by the room terminal
H28
: stop differential (0.6°c default)
H27
: start differential (0.2°c default)
5.2. WAtER tEMPERAtURE
5.2.1. CoMPRESSoR StARt
the entering water temperature (eWt) is compared to the water setpoint (her). When the difference is less than
the last value memorised for any given condition then the compressor can start. this value is typically 5°c but will
depend on the waterflow and outdoor air temperature.
5.2.2. CoMPRESSoR SPEED
the leaving water temperature (lWt) is compared to the water setpoint (her). the compressor speed is adjusted
according to a fuzzy logic algorithm to keep the lWt as close to her as possible. When the two values are close
then the compressor will change speed slowly, however when the two values are more than 2°c apart then the
compressor can change speed up to 8hz per 15s.
the minimum speed is 25hz and the maximum speed is 80hz. these actual min and max speed is automatically
adjusted according to outdoor air temperature. When the outdoor temperature is greater than 25°c then the
maximum speed is reduced and if it is less than 0°c then the minimum speed is increased.
the actual compressor speed status is available in the "i-o" menu in hz.
5.2.2.1. CoMPRESSoR StoP
the compressor will reduce speed if the lWt value remains above the setpoint until it reaches minimum speed.
if the compressor remains at minimum speed for more than 3 minutes with the water temperature above setpoint
then it will stop.
if the compressor speed is less than 30hz for more than 50 minutes, it will stop.
5.3. CoMPRESSoR PRotECtIoN
ALARM LEVEL
ACtIoN
above level 1
compressor speed increase not allowed
above level 1 and increasing or above level 2
small speed decrease
above level 2 and increasing
big speed decrease
above level 3
compressor off
5.3.1. LIMItS
CoMPRESSoR DISCHARGE t
DRIVER AMPS
Model
level 1
level 2
level 3
level 1
level 3
level 3
6
105°c
110°c
115°c
14a
15a
17a
12
110°c
115°c
120°c
21a
22a
28a
16
110°c
115°c
120°c
24a
22a
28a
