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Caledon Controls Ltd
Unit 2 Block 4
Castlehill Ind. Est., Carluke
Scotland ML8 5UF

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TFM103-690V Thyristor fault monitor

TFM103-690V Thyristor fault monitor
TFM103-690V Thyristor fault monitor
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Monitors for short or open circuit devices under load
Suitable for single phase or 3 or 4-wire 3-phase loads
May be used with 2-leg or 3-leg control of a 3-phase load
Suitable for monitoring on nominal 380V to 690V 3-phase supplies or 220V to 690V single phase supplies
Latched or non-latched alarm outputs
Volt free alarm contacts and LED indication
Requires a 24V DC Power Supply
For use with thyristor stacks or solid state relays controlled by a logic signal


This module is intended for on-load monitoring of thyristors for open or short circuits. It can be used with single phase or 3-phase 2 or 3-leg thyristor stacks or solid state relays controlling AC loads operating in burst fire or single cycle burst fire modes and activated by a standard logic signal (not analogue input thyristor controllers). It detects an open or short circuit thyristor and signals an alarm condition via 3 sets of volt free relay contacts. It operates by comparing the voltage across the thyristors in normal operation with the logic command signal which determines whether the thyristors should be on or off.

The thyristor stack must be powered up and a load must be connected for the module to work correctly. 3-phase loads may be connected delta or 3-wire star or, (with 3-leg control only) 4-wire star.

More detailed product information is available on our downloads page

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