Table of Contents
Advertisement
50 Hz
60 Hz
Code
380-420 V / 3 ph
460 V / 3 ph
D
Table 11: Electrical code for motors
5.18 Oil level
Some systems may contain higher than normal refrigerant charges. Systems with large coils, low
ambient condenser flooding, or systems with multiple heat exchangers are among some of the
configurations that may require additional lubricant.
There is no oil sight glass on YBD*K1E compressors.
During the system development phase, adequate oil return from the system to the compressor should
be evaluated and qualified. For this purpose, a sample compressor for lab testing, equipped with an
external oil sight tube, is available from Emerson. See also information in section 3.17 "Compressor
oil return, oil balancing, refrigerant floodback and oil dilution tests".
If an oil regulator is used the oil level should be set within the top half of the oil regulator sight glass.
BOM version XCG contains a stub tube connection 7/8" (22.2 mm) for paralleling on the compressor
housing at oil level height.
5.19 Controlling the digital scroll
The capacity of the digital scroll compressor is controlled via a PWM (pulse-width modulation) signal
to the compressor solenoid valve. The longer the solenoid valve is not energized within the cycle
time, the higher the capacity delivered to the system. During the period when the solenoid valve is
energized, the refrigerant mass flow through the compressor is interrupted while the motor continues
to run at full speed.
Solenoid
Cycle time
Figure 21: Pulse-width modulation principle for digital scroll
The cycle time must not exceed 30 seconds, while the minimum is 10 seconds. The cycle time can
be adjusted within this range. Optimum performance is achieved around 12-second cycle times,
depending on system design.
When developing suitable control concepts and algorithms for digital scroll, special attention must be
paid to compressor protection and minimum requirements for compressor cooling.
Figure 22: Solenoid opening time depending on the load in a 15-second cycle time
NOTE: Emerson offers various controller and driver solutions, such as complete condensing
unit controllers, for capacity regulation and control of the digital scroll solenoid valve. Please
contact your Sales or Application Engineering representative at Emerson for further details.
28
AGL_Ref_DG_YBDK1E_EN_Rev04
Advertisement
Table of Contents
