20 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.
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.
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