Electrical data, connections and wiring
Nominal capacitor value
The Danfoss Heat Pump scroll compressors will
only operate properly in a single direction. Use
a phase meter to establish the phase orders and
connect line phases L1, L2 and L3 to terminals
T1, T2 and T3, respectively. For three-phase
compressors, the motor will run equally well
in both directions. Reverse rotation results in
excessive noise; no pressure differential between
suction and discharge; and suction line warming
rather than immediate cooling. A service
technician should be present at initial start-up to
verify that supply power is properly phased and
that compressor and auxiliaries are rotating in the
correct direction.
Danfoss Heat Pump scroll compressors are
designed to operate for a maximum of 150 hours
in reverse, but as a reverse rotation situation can
go unnoticed for longer periods, phase monitors
are recommended.
At brief power interruptions, reverse rotation can
occur with single phase compressors. In this case
the internal protector will stop the compressor.
It will have to cool down and will restart safely
afterwards.
For three-phase applications the voltage
measured at the compressor terminals for each
phase should be within ± 2% of the average for
all phases.
Phase sequence and
reverse rotation
protection
Voltage imbalance
Internal motor protection
The Danfoss Heat Pump scroll compressors are
equipped with an internal line break protector
mounted on the motor windings. The protector
is an automatic reset device, containing a snap
action bimetal switch.
Internal protectors respond to over-current and
overheating. They are designed to interrupt
motor current under a variety of fault conditions,
such as failure to start, running overload, and fan
failure.
If the internal overload protector trips out, it must
cool down to about 60°C to reset. Depending on
ambient temperature, this may take up to several
hours.
In single-phase compressors, internal protectors
guard against external miswiring, such as
reversing electrical connections to the Run (R) and
Start (S) terminals. In three-phase compressors
the internal protectors provide protection during
secondary single-phase conditions (loss of phase).
If start assist is required, in case of operating
below the nominal voltage, a CSR starting device
is required.
During start-up, the start winding (C-S) is
energised through an electromagnetic potential
relay and a start capacitor.
A permanent (run) capacitor is wired between the
start winding (C-S) and the run winding (C-R).
CSR wiring
PSC wiring
Run capacitor
HHP015T5LP6
40
HHP019T5LP6
60
HHP021T5LP6
60
HHP026T5LP6
70
HHP030T5LC6
50
HHP038T5LC6
55
Start
Capacitor
Potential
Relay
1
2
5
C
S
R
Line
Run
Capacitor
14
FRCC.PC.017.A2.02
Application Guidelines