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C6.2.38/0719/E
4.3.1 Motor windings
YBVH* compressors feature a three-phase brushless permanent magnet motor. It is exactly the
same whether the drive supply is single-phase or three-phase. The motor is connected in star.
The motor insulation material is class "F" for maximum allowable operating temperatures according
to IEC 34-1 or DIN 57530.
4.4 Protection devices
Fuses must be installed before the drive. The selection of fuses has to be carried out in accordance
with VDE 0635, DIN 57635, EC 269-1 or EN 60-269-1.
4.5 Crankcase heating function
CAUTION
Motor overheating! Compressor damage!
The crankcase heating function
must not be energized when the system is in a vacuum or if there is no
refrigerant charge in the system. The system low-pressure cut-out control can
be used as an indicator of the presence of refrigerant charge.
IMPORTANT
Oil dilution! Bearing malfunction!
Follow the off-cycle migration statement
described below for long term reliability and to minimize nuisance associated
with flooded start conditions.
Contrary to the standard fixed-speed Copeland Scroll compressors, the YBVH* models do not
require any optional external crankcase heater to be mounted on the compressor.
Instead, the ED3 drive has a programmable feature that will utilize the motor windings to provide up
to 50 Watts DC of heating to serve as a crankcase heater.
The crankcase heating function activation is recommended when the system charge exceeds the
refrigerant charge limit indicated in
Table 6
below.
If this function is required, the crankcase heating function must be used and the power has to be
determined by tests across the envelope for winter and summer situations.
Compressor
Refrigerant charge limit
YBVH021
YBVH029
1.2 kg
YBVH046
1.2 kg
Table 6: Refrigerant charge limit
NOTE: At first start, the crankcase heating function must be turned on a minimum of 12 hours
prior to starting the compressor.
4.6 Pressure safety controls
4.6.1 High-pressure protection
A high-pressure cut-out control must be used in all applications to avoid abnormally high operating
pressures. The maximum cut-out setting should be defined referring the high-side PS (maximum
allowable pressure) according to the requirements of applicable standards and directives.
The high-pressure cut-out limiter has to be connected to the ED3 drive
– see the wiring diagram. The
output is a 5VDC signal. Normally the high-pressure cut-out limiter must be closed. If the limiter is
open, the drive will not operate.
NOTE: For the connection of the high-pressure limiter to the drive, please refer to the
Emerson User Manual for ED3.
4.6.2 Low pressure protection
WARNING
Operation under ambient pressure! Fire hazard!
During operation under
ambient pressure, a flammable mixture can form inside the system. Make sure
that air does not enter the system.