High Voltage Test - Danfoss VZH028 Application Manuallines

Application Guidelines

High voltage test

38
FRCC.PC.034.A2.02
Installation
For brazing the suction and discharge
connections, the following procedure is advised:
• Make sure that no electrical wiring is connected
to the compressor.
• Protect painted surfaces on the terminal box
and compressor from torch heat damage (see
diagram).
• Remove the Teflon gaskets when brazing
rotolock connectors with solder sleeves.
• Use only clean, refrigeration-grade copper
tubing and clean all connections.
• Use brazing material with a minimum of 5%
silver content.
• Purge nitrogen or CO through the compressor
2
in order to prevent against oxidation and
flammable conditions. The compressor should
not be exposed to the open air for extended
periods.
• Use of a double-tipped torch is recommended.
• Apply heat evenly to area A until the brazing
temperature is reached. Move the torch to
area B and apply heat evenly until the brazing
temperature has been reached there as well,
and then begin adding the brazing material.
Move the torch evenly around the joint, in
applying only enough brazing material to flow
the full circumference of the joint.
• Move the torch to area C only long enough to
draw the brazing material into the joint, but not
into the compressor.
Carry out a high voltage test by short-circuiting
terminals U, V, W, L1, L2 and L3. Energize by max.
1920 V DC for code G compressors and 1460 V DC
for code J compressors for one second between
this short-circuit and the chassis. When running
high voltage tests of the entire installation,
frequency converter and compressor electrical
Single compressors
• Remove all remaining flux "once the joint has
been soldered" with a wire brush or a wet cloth.
Remaining flux would cause corrosion of the
tubing.
Ensure that no flux is allowed to enter into the
tubing or compressor. Flux is acidic and can cause
substantial damage to the internal parts of the
system and compressor.
The polyolester oil used in VZH compressors
is highly hygroscopic and will rapidly absorb
moisture from the air. The compressor must
therefore not be left open to the atmosphere
for a long period of time. The compressor fitting
plugs shall be removed just before brazing the
compressor. The compressor should always be
the last component brazed into the system
Before eventual unbrazing the compressor or
any system component, the refrigerant charge
must be removed from both the high- and
low-pressure sides. Failure to do so may result in
serious personal injury. Pressure gauges must be
used to ensure all pressures are at atmospheric
level.
For more detailed information on the appropriate
materials required for brazing or soldering, please
contact the product manufacturer or distributor.
For specific applications not covered herein,
please contact Danfoss for further information.
motor compressor test can be conducted
together. When conducting a high voltage test
make sure the system is not under vacuum: this
may cause electrical motor compressor failure.
Please note, it is note recommended that a high-
voltage test be carried out too often as it may
damage the motor.