TM206
33 of 35
Issue 1.0
17 Internal indications
17.1
Watchdog
Indicates that the processor has failed to correctly execute code and has been re-started by the
watchdog circuit. The
WATCHDOG RESET
switch must be pressed to clear the Watchdog fault
condition.
If the fault does not clear the ECU is probably damaged and needs the circuit board replacing.
17.2
System
fuse
Indicates that the ECU main fuse has been overloaded and the ECU has shut down. Remove and review
all loads then re-connect one at a time.
17.3 Man.
Release
Indicates that either the front panel mounted or a remotely connected Manual release control has been
operated. This indication can only be cleared by power cycling the module or pressing the processor
reset switch.
18 Power supply
The ECU requires a 230V (+10%/-15%), 50/60Hz, AC mains power supply which connects to the fused
terminal block labelled “230V”.
The ECU has a 20mm T2A L250V mains fuse.
The fuse should only be replaced with fuses of the same or similar types.
The maximum loading on the power supply must be carefully considered when connecting externally
powered equipment such as sounders and solenoids
Exceeding the maximum power supply rating may cause a fuse or other protective device to
operate and render the equipment inoperative until the fuse is replaced or protective devices are
reset.
The table below can be used to calculate the loading of the ECU.
Current
in
milliamps
ECU Max alarm load
105
ECU total sounder load
ECU Extinguishing output load
ECU Aux 24V supply
TOTAL LOAD (must be less than 3A)
The output voltage of the power supply is 28V DC +/- 2V and the total current rating is 4A.
The incoming mains cable should be routed well away from other lower voltage wiring by a distance of at
least 50mm.
Mains wiring should include an earth conductor, which is securely bonded to the building earth and
should enter the enclosure as close as possible to the mains terminal block. Mains wires should be kept
very short inside the enclosure and secured together close to the mains terminal block with a cable tie.
The maximum capacity batteries that should be fitted are 7Ah.
The maximum current drawn from the batteries when the main power source is disconnected is 4 Amps.
