Specifications

Delayed Transition Transfer Switching
Fig. 3 Delayed Transition Transfer Switch
rated 4 pole 1200 amperes.
ASCO Delayed Transition Transfer Switches are
designed to provide transfer of loads between power
sources with an intentional load disconnect position
for an adjustable period of time. Applications include
older style variable frequency drives, rectifier banks,
and specialized medical equipment.
• Available 150 through 4000 amperes.
• Utilizes reliable, field proven solenoid
operating mechanisms.
• Mechanical interlocks to prevent direct
connection of both sources.
• Indicator light (16mm, industrial grade
type LED) for load disconnect position.
• Adjustable time delay for load
disconnect position.
7000 Series Switching Solutions
Closed-Transition Transfer Switching
ASCO Automatic Closed-Transition Transfer Switches
feature main contacts that overlap, permitting the
transfer of electrical loads without power interruption.
The switch transfers in a make-before-break mode if
both sources are within acceptable parameters. Control
logic continuously monitors source conditions and auto-
matically determines whether the load transfer should
be open (conventional non-overlap mode) or closed
transition. Available 150 through 4000 amperes.
Closed-Transition Transfer within 5 electrical degrees is
achieved passively. Active control of the engine gener-
ator is not required. Therefore, no additional control
wire runs are required between the ATS and engine gen-
erator set governor. Plus, protective relaying may not be
required under normal operation since the contact over-
lap time is less than 100 milliseconds (consult your local
utility on protective relay requirements).
Failure to synchronize annunciation and extended paral-
lel time protection is built-in to all 7000 Series closed
transition controls to prevent abnormal operation.
Fig. 2 Closed-Transition Bypass Transfer Switch
rated 4 pole 800 amperes.
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