20
C6.2.24/1014-0215/E
Compressors ZBD58K* to ZBD114K* and ZFD41K5E:
These models have no internal
temperature protection and therefore require an external thermostat or a discharge temperature
sensor (NTC thermistor) mounted as close as possible to the discharge fitting in order for the
Digital Scroll controller to operate properly. For best response the sensor should be insulated.
Compressors ZFD13KVE to ZFD25KVE:
For low temperature applications with
R404A
, these
compressors could be used with the NTC thermistor, connected to the digital Scroll controller.
For low temperature applications with
R407A, R407F, R448A and R449A
the DTC valve bulb
(for the wet vapour injection system) must replace the existing NTC sensor located at the side of
the compressor top cap. Since there is no more connection possibility for the NTC sensor bulb,
the previous NTC sensor has to be removed and the controller, eg, ALCO EC3-D*, has to be
modified (disable discharge sensor input). A new discharge gas thermostat must be installed on
the discharge line. DO NOT use the previous solution NTC controller as a discharge
temperature protection since its rating is not suitable for R407A, R407F, R448A and R449A.
The R404A, R407A, R407F, R448A and R449A
dedicated discharge thermostat has a cut-out
setting of 130°C ± 4K with closing at 101°C ± 8K.
The thermostat should be installed approximately
120 mm from the discharge valve outlet (see
Figure 25
). It must be insulated in order to avoid
improper functioning due to false readings (see "X"
in
Figure 25
).
4.5 High potential testing
WARNING
Conductor cables! Electrical shock!
Shut off power supply before high-
potential testing.
CAUTION
Internal arcing! Motor destruction!
Do not carry out high-voltage or
insulation tests if the compressor housing is under vacuum.
Emerson Climate Technologies subjects all Scroll compressors to a high-voltage test after final
assembly. Each motor phase winding is tested, according to EN 0530 or VDE 0530 part 1, at a
differential voltage of 1000V plus twice the nominal voltage. Since high-voltage tests lead to
premature ageing of the winding insulation further additional tests of that nature are not
recommended.
If it has to be done for any reason, a lower voltage must be used. Disconnect all electronic
devices, eg, motor protection module, fan speed control, etc prior to testing.
Figure 22: Discharge temperature protection
recommended position
X