Electrical Connection; General Recommendations; Electrical Installation; Part-Winding Motors (Yy/Y) - Code A - Emerson Copeland 4MTL-05 Application Manuallines

4

Electrical connection

4.1

General recommendations

The compressor terminal box has a wiring diagram on the inside of its cover. Before connecting the
compressor, ensure that the supply voltage, the phases and the frequency match the nameplate
data.
The knockouts have to be removed before the electrical glands can be installed. First make sure that
the terminal box is closed with the terminal box cover. We recommend to use a subland twist driller
to avoid any damage to the box while removing the knockouts.
Figure 21: Terminal box knockouts
4.2

Electrical installation

All compressors can be started Direct-On-Line.
The position of bridges required for Direct-On-Line start (depending on the type of motor and/or
mains voltage) is shown in paragraph 4.2.4 "Terminal box isolators and jumper position".
4.2.1 Part-winding motors (YY/Y) – Code A
A part-winding motor contains two separate windings (2/3 + 1/3) which are internally connected in
star and operated in parallel. The voltage cannot be modified by changing the electrical connections
as the motor is only suitable for one voltage.
The first part-winding, ie, the 2/3 winding on terminals 1-2-3, can be used for part-winding start
(remove the bridges!). After a time delay of 1 ± 0.1 seconds the second part-winding, ie, the 1/3
winding on terminals 7-8-9, must be brought on line.
4.2.2 Part-winding motors (YY/Y) – Code F
Part-winding motors contain two separate windings (Code F motors always split by 1/2 + 1/2) which
are internally connected in star and operated in parallel. The voltage cannot be modified by changing
the electrical connections as the motor is only suitable for one voltage.
The first part-winding, ie, the 1/2 winding on terminals 1-2-3, can be used for part-winding start
(remove the bridges!). After a time delay of 1 ± 0.1 seconds the second part-winding, ie, the second
half winding on terminals 7-8-9, must be brought on line.
4.2.3 Star / Delta motors (Y/∆) – Code E
On this three-phase motor, the 6 ends of the three windings are led into the terminal box of the
compressor via cable bushings.
The star or delta connection as required is achieved by means of connection bars in the terminal box
or via controlled contactors. Thus, the motor can be run at the operating voltage.
The voltage version L (motor code EWL) of this motor allows operation at two voltages, a lower
voltage, eg, 230 V in delta connection, and a higher voltage, eg, 400 V in star connection.
The voltage version M or D (motor code EWM for 50 Hz or EWD for 60 Hz) of this motor shall be
used for full-load in delta connection. Here the star connection is used primarily for starting (Star /
Delta start).
However, the EWM motor can also be used for power supply with voltages of 690 V / 3 Ph / 50 Hz
in star connection (only on the M version).
18
Twist driller
AGL_Stream_ST_4MTL_4MSL_E_Rev01