!
USER MANUAL – Release 1.2 of 01/01/2010
Page 104 of 191
Version: 02/03/2010
27.4 DESCRIPTION OF PART WINDING START-UP
This type of start-up allows to drastically reduce the peak current on compressor start-up. It is used with
alternative hermetic, semi-hermetic or screw compressors with medium-large dimensions.
Two relay outputs must be configured for every compressor:
One as compressor 1 PW start-up n° 1
One as compressor 1 PW start-up n° 2
This is because the compressor electric motor is composed of two separate windings that must be powered
at a distance of about 1 second (time can be set using parameter CO13) from each other.
It is possible to configure up to 8 relay outputs for a maximum of 4 compressors with Part Winding start-up
27.5 PART WINDING START-UP OF A COMPRESSOR
With request from the heat regulator, first the relay configured as compressor 1 PW n° 1 is excited (relay K1
Fig. 2), after the time set in the par. CO13 the second relay configured as compressor 1 PW n° 2 (relay K2
Fig. 2). Compressor start-up is concluded at this point.
However, when temperature control requires the switch-off, the 2 relay outputs are lowered at the same time
Fig 2
27.6 PART WINDING START-UP OF A COMPRESSOR/S WITH 1 OR MORE PARTIALISATIONS
The start-up procedure is the same as that stated above (par. 14.5). If compressor/s with partialisations have
been configured if switch-on is requested at full compressor load, first the partialisation solenoid is excited
(always the step with the lowest index, the part. N° 1) and after 1 second (fixed time) the relay configured is
activated as compressor 1 PW n°1 (relay K1 Fig. 2). With the start-up procedure concluded, the delay CO15
even if working at minimum power has been enabled from the parameter but the heat regulator does not
request switch-on, the solenoid is unexcited. If the time set in Par. CO15 = 0 the function is disabled
27.7 DESCRIPTION OF STAR DELTA START-UP
This type of start-up allows to drastically reduce the peak current on compressor start-up. It is used with
alternative hermetic, semi-hermetic or screw compressors with large dimensions.
n° 3 relays per compressor are used
27.8 STAR DELTA START-UP OF A COMPRESSOR
Three relay outputs must be configured for every compressor:
N° 1 relay output configured as comp. n° 1 line n° 1 relay (relay K1 Fig.3)
N° 1 relay output configured as comp. n° 1 line n° 2 relay (relay K3 Fig.3)
N° 1 relay output configured as star centre (relay K2 Fig.2)
On switch-on request the start centre relay is excited (relay K2 Fig.2). After 1 second (time we set) the line n°
1 relay is excited (relay K1 Fig.3). They function simultaneously for the time set in parameter CO13. On
expiry of time CO11 the start centre relay is unexcited (relay K2 Fig.2) and after the time set in par. CO14
the line n° 2 relay is excited (relay K3 Fig.3). Compressor start-up is concluded at this point.
When the line n° 1 and n° 2 relay outputs must be off (relay K1 /K3 Fig.3) they are lowered simultaneously.
