KT-420-4 // PDF Download
49
4.3
To be observed for open drive compressors
Select motor and frequency inverter in agreement with the manufacturers.
!
!
NOTICE
Risk of motor damage due to insufficient cooling!
Ensure that the motor is sufficiently cooled at every speed! Observe the application limits provided by the
motor manufacturer.
Motor protection
Besides a typical line protection switch, the use of thermistor thermal motor winding protection is additionally re-
commended to ensure that the motor is only operated at permissible temperatures.
Shaft coupling and seal
Select the coupling carefully (see BITZER SOFTWARE). For low speed / frequency operation, a shaft coupling with
sufficient inertia must be selected (see also Technical Information
4.4
To be observed for tandem and 2-stage compressors
Oil equalisation for semi-hermetic tandem compressors
When tandem compressors are operated with frequency inverter, the oil level between both compressor sides may
differ. Thus, an oil level control system or oil and gas equalisation must be installed between the two sides.
RI valve for semi-hermetic 2-stage compressors
For 2-stage compressors, sufficient superheat at the refrigerant injection (RI) valve must be ensured over the entire
speed range. Therefore select a valve suitable for the application.
5
Suitable protection devices
The devices SE-B* as well as the compressor module CM-RC-01 are suitable for operation of reciprocating com-
pressors with frequency inverter.
Protection devices SE-B*
!
!
NOTICE
Potential failure of the compressor protection device and the motor due to improper connection and/or faulty
operation!
The terminals M1-M2 or T1-T2 on the compressor and B1-B2 on the protection device as well as its two
sensor cables must not come into contact with the control voltage or operating voltage!
Compressor module CM-RC-01
. For mounting the CM-RC-01 add-on kit, see also:
•
for compressors 4JE .. 4FE and 6JE .. 6FE
•
for compressors 4VES .. 4NES
•
for compressors 4FES .. 4BES
