Heater Break Alarm - Honeywell CD3000M-3PH User Manual

User's Manual

6.4 Heater Break Alarm

Heater Break Alarm is a microprocessor based circuit to diagnose partial or total load failure and
short circuit on SCR and fuses failure.
• discrimination better than 20%;
• latching alarm plus reset;
• relay output 0.5A at 125VAC.
Minimum current 3A. If load current is below this value make two turns or more
around current transformer. H.B. circuit also diagnose fuse failure.
H.B. circuit reads load current via a current transformer 25-50/0.05 or 100/0.05 depending on
thyristor size.
6.4.1 Heater Break Alarm indication
LED STATUS
SC
HB
= OFF = ON
The thyristor unit is supplied with a normally closed (N/C) contact.
In alarm condition and without auxiliary voltage the contact is closed (relay coil not
energized). In normal condition (no alarm) the contact is open (relay coil energized).
6.4.2 Reset
To reset Heater Break Alarm open RESET contact on terminal 3-4.
CD3000M-3PH up to 90A
DESCRIPTION
SCR OK
SCR short circuit
Laod OK
Load Fault
= Flashing
25
Honeywell
www.honeywell.com/imc