Page 6 - WENZHOU ZHUOCHAO ELECTRIC CO.,LTD.

Purpose
SZW26 series change-over switch is mainly applicable to the electrical circuits (AC 50Hz, rated operating voltage 440V and below, DC voltage
240V and below, rated current up to 160A) to manually connect or disconnect circuit infrequently as control or change-over purpose. It can
also directly control three-phase asynchronous motor and can be used for master control and circuit measurement. With wide application, it
can serve as circuit control switch, equipment test switch, motor control switch, master control switch, and electric welding machine switch
etc.
Products conform to the standard of GB/T14048.5.

Normal operating conditions

1.Ambient air temperature does not exceed +40℃ , and its average temperature within 24 hours does not exceed +35℃ ;
2.Lower limit of ambient air temperature does not exceed -25℃ ;
3.The altitude of installation site does not exceed 2000m;
4.When maximum temperature is +40℃ , air relative humidity does not exceed 50%, higher relative humidity is allowed at a lower
temperature. For example, relative humidity reaches 90% in time of 20℃ . It’s required to adopt special measures on the dew condensates
that occasionally form due to temperature changes.

Model meaning of change-over switch used for master control Purpose Purpose
code
> Model meaning of change-over switch used for master control
Q Direct starting
SZW 26 - □ · □ □ / □ N Reversible change-over
S Two-speed motor speed variation
Two-speed motor speed variation,
Contact system section number SN
reversibility
Operating chart serial number
Note: Adopt 60° change-over when purpose
Characteristic code
code is Q, S, N, and adopt 45° change-over
Change-over angle code
when purpose code is SN.
Specification code
(conventional heating current value) 1.Classify by purpose
Design code 1.Change-over switch used for main circuit
Enterprise code change-over
2.Change-over switch used for direct
control motor
3.Change-over switch used for master
> Model meaning of change-over switch used for direct control motor
control and measurement
SZW 26 - □ / □ □ · □
2.Classify by operating mode
1.Change-over switch used for main circuit
change-over
Contact system section number
2.Change-over switch used for direct
Purpose code control motor
Rated power of controllable 3.Change-over switch used for master
three-phase AC motor control and measurement
Specification code 3.Classify by contact system
(conventional heating current value) 1.Positioning type change-over switch has
Design code 1~12 sections. (The switch with 63A and
above has 8 sections only.)
Enterprise code
2.Self-resetting type change-over switch
has 1~3 sections.
Utilization category 3.Change-over switch used for direct
control motor mainly has 1~6 sections.
See following table for utilization category of change-over switch
Current type Category code Purpose
AC-21A On-off resistive load, including appropriate overload;
AC-22A On-off resistance and inductive mixed load, including appropriate overload;
AC-23A On-off motor load or other highly inductive load;
AC AC-2 Slip-ring motor: starting, plug braking and reversal, sectioning;
AC-3 Cage type motor: starting, breaking motor during operation;
AC-4 Cage type motor: starting, reverse braking and
AC-15 Control AC electromagnet load (larger than 72VA);
AC AC-13 Control DC electromagnet

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