Technical Specifications

ASCO Power Technologies, Florham Park, New Jersey 07932 800-937-ASCO www.ascopower.com
01-2009 2 Publication xxxx
PART 2 PRODUCTS
2.01 Mechanically Held Transfer Switch
A. The transfer switch unit shall be electrically operated and mechanically held. The
electrical operator shall be a momentarily energized, single-solenoid mechanism.
Main operators which include overcurrent disconnect devices, or linear motors shall
not be acceptable. The switch shall be mechanically interlocked to ensure only two
possible positions, normal or emergency.
B. The switch shall be positively locked and unaffected by momentary outages so that
contact pressure is maintained at a constant value and temperature rise at the
contacts is minimized for maximum reliability and operating life.
C. All main contacts shall be silver alloy composition.
D. Inspection of all contacts shall be possible from the front of the switch without
disassembly of operating linkages and without disconnection of power conductors.
A manual operating handle shall be provided for maintenance purposes. The handle
shall permit the operator to manually stop the contacts at any point throughout their
entire travel to inspect and service the contacts when required.
E. Designs utilizing components of molded-case circuit breakers, contactors, or parts
thereof which are not intended for continuous duty, repetitive switching or transfer
between two active power sources are not acceptable.
F. Where neutral conductors are to be solidly connected, a neutral terminal plate with
fully-rated AL-CU pressure connectors shall be provided.
2.02 Microprocessor Controller with Membrane Interface Panel
A. The controller shall direct the operation of the transfer switch. The controller's
sensing and logic shall be controlled by a built-in microprocessor for maximum
reliability and minimum maintenance. The controller shall be connected to the
transfer switch by an interconnecting wiring harness. The harness shall include a
keyed disconnect plug to enable the controller to be disconnected from the transfer
switch for routine maintenance.
B. The controller shall be self contained and be mounted separate from the transfer
switch unit for safety and ease of maintenance. Sensing and control logic shall be
provided on a printed circuit board.
C. The controller shall meet or exceed the requirements for Electromagnetic
Compatibility (EMC) as follows:
1. IEC 1000-4-2 (1995) – Electrostatic Discharge Immunity
2. IEC 1000-4-3 (1995) – Radiated EM Field Immunity
3. IEC 1000-4-4 (1995) – Electrical Fast Transient Immunity
4. IEC 1000-4-5 (1995) – Surge Immunity
5. IEC 1000-4-6 (1995) – Conducted RF Disturbance Immunity
6. EN 55011 – Radiated and Conducted Emissions
7. EMC Directive 93/68/ECC CISPR Class A