20
AGL_Ref_ST_YFK1E_EN_Rev01
Cable glands have an inf luence on the protection class of the terminal box . Emerson strongly
recommends using appropriate cable glands according to EN 50262 in order to reach the rated
protection class. Examples of correct electrical installations are shown in
Figure 19
below.
Figure 19: IP54 T-Box and correct electrical installation with cable gland
4.4 Motor insulation
The motor insulation material is class "B" (T
F
DN) within maximum allowable operating temperatures
according to IEC 34-1 or DIN 57530.
4.5 Motor protection
In addition to the internal motor protection, f uses must be installed before the compressor. The
selection of f uses has to be made according to EN 60269-1 or EN 60204-1 and compressor
maximum operating current (MOC). Not installing f uses bef ore the compressor or selecting
inappropriate fuses may result in compressor failure.
4.6 High potential testing
WARNING
High potential testing in a flammable atmosphere! Fire hazard!
For A2L
ref rigerant systems, make sure the atmosphere is non-f lammable before
perf orming high potential testing. DO NOT perf orm any high potential test
when the compressor is charged with flammable ref rigerant.
WARNING
Conductor cables! Electrical shock!
Shut of f power supply bef ore high
potential testing.
CAUTION
Internal arcing! Motor destruction!
Do not perform high-voltage or insulation
tests if the compressor housing is under vacuum.
Emerson subjects all scroll compressors to a high-voltage test after f inal assembly. Each motor
phase winding is tested according to EN 60034-1 at a dif ferential voltage of 1000 V plus twice the
nominal voltage.
Since high-voltage tests lead to premature ageing of the winding insulation, f urther additional tests
of that nature are not recommended. However, if it has to be done f or any reason, it shall not be
made with the compressor charged with refrigerant. Run the test with a lower voltage, as described
above. Disconnect all electronic devices, eg, motor protection module, fan speed control, etc prior to
testing.
Special attention should be paid when perf orming a high potential test and reading the Megohm
resistance on A2L compressors, as such tests can induce an electrical arc and cause a fire hazard.
For the same reason, compressors removed f rom a system with A2L ref rigerant will need to have
the oil drained and a nitrogen purge introduced to f lush any remaining ref rigerant f rom the
compressor prior to high potential testing and Megohm resistance reading.
