GTW1 (DW45) series air circuit breakers (ACB) are used to protect the circuit from
overload, under-voltage, short-circuit and earth fault in distribution electric
net with AC50Hz, rated operation voltage 400/690V, rated current 400A 6300A. Frame
under 630A can be used as overload, under-voltage and short-circuit protection
for electric motors. The key part uses intelligent release unit to ensure selective
protection ways to make the circuit release from unnecessary power-off and
high operation reliability. The products conform to IEC 60947-2, IEC 60947-4
standards.

Normal operation and mounting requirements:
1) Altitude for installation: <2000m
2) Ambient temperature: -5 ~ +40oC (minimum value within
-10 ~ -25oC applicable, >+40oC or <-25oC need
negotiation)
3) Humidity:
a) Relative humidity of atmosphere: <50% when the temperature
kept under +40oC
b) Higher relative humidity can be permitted at lower temperature
c) Monthly average humidity is under 90% when the min. monthly
average humidity is under +25 in the most watery month
d) Meanwhile the coagulate water occurred on the surface of
products should be taken into account
4) Pollution degree: 3
5) Installation category: IV; for auxiliary circuit the under-voltage
release coil and primary coil of voltage transformer are the same
with breaker, the others are construction features

This kind of product is divided into two types: withdrawable and fixed type. Withdrawable
type is combined by contact system, intelligent release, manual operation
mechanism, electric operation mechanism and mounting board; withdrawable type
are combined by contact system, intelligent release, manual operation mechanism,
electric operation mechanism and withdraw base.

Breakers are solid distributing. It has compact construction and small volume. Contact
system is in the insulation bottom-board. Phase-contacts are disconnected
to form a little scope. The intelligent release, manual operation mechanism and
electric operation mechanism are in the front the contact system one by one and
are independent units. If one unit is damaged you can disassemble it to replace
for a new one.

Because the product only uses one group of contacts (omit the arcing contacts) to
decrease operation force of contacts and accelerate the procedure of breaking,
the contact system uses parallel method to decrease electric exclusion force and
to improve the electric stability. Contacts, soft connecting and bus bar all use
welding to low the touching resistance and power consumption.

The arc-damping chamber is made by insulation material. Contact system and arc-damping
system are placed between upper base and bottom base both of which are made
from high strength and excellent electric performance insulation materials. Each
phase is designed as independent arc-damping chamber while contacts are assembled
on the insulation brackets to prevent from phase-to-phase short circuit. When
breaking short circuit current the air can only give out to the upper position
(ensure the reliability of down line-in wiring way).

The ACB is designed with the operating mechanism charged either manually or electrically
for closing and opening. Its closing speed is independent of the speed of
electric and manual operation. The energy stored springs of the ACB is charged
through a cam. The ACB is designed with three positions (including trip free function).

Intelligent release has such functions as below:
1) Reverse long time delay for over load protection, reverse short-time
delay, definite short-time delay, and instantaneous for short-circuit
protection
2) Earth fault protection
3) Overload alarm
4) Test
5) Load monitoring
6) Functional display
7) Diagnostic
8) MCR
9) Thermal memory
10) Contact abrasion indication
11) Fault memory