Tyco Galaxy SC Controller User Manual

Tyco Electronics Galaxy SC Controller J85501F-1
Issue 13 February 2001 Feature Descriptions 7 - 34
J874 series rectifiers. The Galaxy SC places the rectifier in standby
mode until the rectifier is repaired, in order to protect the rectifier.
There is no overriding condition for this standby mode.
External Rectifier
Sequencer
The external rectifier sequencer is used to regulate which rectifiers will
be on following a commercial power failure and subsequent
engine-alternator run (and vice-versa). The Galaxy SC constantly
monitors Transfer [TR] signals from the external sequence controller.
There are 4 signals from the external sequencer: TR1, TR2, TR3 and
TR4. Each TR signal controls multiple rectifiers, and upon receipt, the
Galaxy SC will place the associated rectifiers in standby mode.
• TR1 controls rectifiers 1, 2, 9, 10, 17, and 18.
• TR2 controls rectifiers 3, 4, 11,12, 19, and 20.
• TR3 controls rectifiers 5, 6, 13, 14, 21, and 22.
• TR4 controls rectifiers 7, 8, 15, 16, 23, and 24.
Note that a ground signal on a TR lead immediately places all rectifiers
in its group in standby mode. Once the ground is removed, the rectifiers
are turned back on with intervening one-second delays to preclude
inrush difficulties.
If the external sequence controller places a rectifier in standby mode, the
External Transfer Shutdown alarm is created.
Internal Rectifier
Sequencer
The Galaxy SC can be used to select which rectifiers are used when the
plant is running on engine-alternator AC. The Galaxy SC receives two
signals, Engine Transfer (ETR) and RO, which indicate the transfer of
AC from commercial AC to engine-alternator AC or vice-versa.
The Galaxy SC monitors the ETR signal, which indicates a transfer of
AC source. Upon activation of the ETR signal (a ground), all rectifiers
are placed in standby mode. The Galaxy SC does not know yet whether
the new source for the AC is the commercial AC or the engine-alternator
AC, but must wait until the engine-alternator is up to its rated frequency
and voltage. This waiting period is a user programmable time period.
The RO signal, which previously was in a non-deterministic state, is
now read to determine whether the AC switch is to commercial AC or
the engine-alternator AC (a ground). If the switch is to commercial AC,
all rectifiers are turned back on using a fixed 1 second interval, to avoid
inrush. Otherwise, the engine-alternator is the AC source, which has a
limited capacity, thus a smaller user selectable set of rectifiers are used.
Initially, all rectifiers are used. Each rectifier in this set is turned on

Tyco Galaxy SC Controller Specifications

General

Brand	Tyco
Model	Galaxy SC Controller
Category	Controller
Language	English