Electrical installation
Cables general
Always comply with national and local regula-
tions on cable cross-sections.
Tightening-up Torque
CD size Cable for:
Tightening
up torque
3-7.5 kW
Line, load sharing motor
Compressor cable
1.8 Nm
11-22 kW
Line, load sharing motor
compressor cable
1.8 Nm
11-22 kW
Motor compressor cable
1.8 Nm
Relay
0.5 - 0.6 Nm
Earth
2 - 3 Nm
• Removal of knockouts for extra cables
- Remove cable entry from the frequency conver-
ter (Avoiding foreign parts in the frequency
converter when removing knockouts)
- Cable entry has to be supported around the
knockout you intend to remove.
- The knockout can now be removed with a
strong mandrel and a hammer.
- Remove burrs from the hole.
- Mount Cable entry on frequency converter.
• Connection to Mains and Earthing
How to connect to mains and earthing (A2 and
A3 enclosure).
- Make sure the CD 302 is properly earthed.
Connect to earth connection (terminal 95). Use
screw from the accessory bag.
- Place plug connector 91, 92, 93 from the acces-
sory bag onto the terminals labelled MAINS at the
bottom of CD302.
- Connect mains wires to the mains plug connec-
tor.
Connection to Mains and Earthing
How to connect to mains and earthing (B1 and
B2 enclosure)
• IT Mains
Check that mains voltage corresponds to the
mains voltage of the CD302 name plate.
L1, L2, L3 mains have to be connected preferably
clockwise direction
3 Phase
Power
Input
91 (L1)
92 (L2)
93 (L3)
95 PE
• Motor compressor connection
Motor compressor cable must be screened / ar-
moured. If an unscreened / unarmoured cable is
used, some EMC requirements are not complied
with. For more information, see EMC specifica-
tions.
- Fasten decoupling plate to the bottom of CD302
with screws and washers from the accessory bag.
- Attach motor compressor cable to terminals 96
(U), 97 (V), 98 (W).
- Connect to earth connection (terminal 99) on
decoupling plate with screws from the accessory
bag.
- Insert terminals 96 (U), 97 (V), 98 (W) and motor
compressor cable to terminals labelled MOTOR.
Fasten screened cable to decoupling plate with
screws and washers from the accessory bag.
U, V, W for motor compressor need to be clockwise
connected. Note that VTZ compressors can rotate
on both directions, but when used in manifolded
sytems all compressors must have the same rota-
tion direction to avoid vibration interferences.
≤7.5 kW IP 55
11 - 22 kW IP 21/55
≤7.5 kW IP 20
• Motor compressors cables
Correct dimensioning of motor compressor cable
cross-section and length is described in the appli-
cation manual.
- Use a screened/armoured motor compressor
cable to comply with EMC emission specifica-
tions.
- Keep the motor compressor cable as short as
possible to reduce the noise level and leakage
currents.
- Connect the motor compressor cable screen to
both the decoupling plate of the CD302 and to
the metal cabinet of the motor compressor.
- Make the screen connections with the largest
possible surface area (cable clamp). This is done
by using the supplied installation devices in the
CD302.
• Electrical installation of motor compressor
cables
- Screening of cables :
Avoid installation with twisted screen ends (pig-
tails). They spoil the screening effect at higher
frequencies. If it is necessary to break the screen
to install a motor compressor isolator or motor
compressor contactor, the screen must be conti-
nued at the lowest possible HF impedance.
- Cable length and cross-section :
The frequency converter has been tested with a
given length of cable and a given cross-section
of that cable. If the cross-section is increased, the
cable capacitance - and thus the leakage current
- may increase, and the cable length must be re-
duced correspondingly.
- Switching frequency : The switching frequency
is factory set at 3.5 kHz.
- Aluminium conductors : Aluminium conduc-
Instructions
4 | AN000086420674en-000201
© Danfoss | DCS (CC) | 2019.04
