Technical data

20
Envoy Installation, Commissioning & Operating Manual
Zone Circuits
The default mode of operation assumes that the zone circuit is configured for open and short circuit fault
monitoring, and detector removal monitoring, i.e. detector bases are fitted with a diode.
If these conditions do not apply, e.g. when connecting a circuit from an existing system, the operating
parameters for each affected zone must be changed. Refer to the Engineering Options section for
details.
It is recommended that each zone is connected in turn and its operation proved before moving on to the
next zone.
Check that all detectors are fitted into their bases and that a 4K7 Ohm resistor has been fitted to the last
device. Remove the 4K7 Ohm resistor from the selected zone terminals and connect the zone pair,
observing polarity.
If a zone fault is indicated, investigate and clear before proceeding to the next circuit. If necessary refer
to the fault location chart on page 22.
Continue to connect each zone circuit until all are connected and fault free.
It may be preferable to test the operation of zone devices before proceeding with the connection of
sounders.
Sounder Circuits
The Master PCB has two sounder circuits and each hy-spec zone card has one sounder circuit that by
default operate in “constant sounder” mode on the activation of any zone. “ Zone of origin operation”
can be achieved by changing the operating parameters. Refer to Engineering Options.
Sounders must be polarised and suppressed and connected in a parallel circuit with no spurs or tees.
Ensure that the load of the sounders is within the individual circuit limits, and that the total load does
not exceed the panel limits, taking into account any additional load imposed by auxiliary circuits,
repeaters, etc.
Remove the 4K7 Ohm resistor from the relevant sounder circuit terminals and connect the circuit pair,
observing polarity. Ensure that a 4K7 Ohm resistor is fitted in parallel with the last device on the circuit.
Clear any faults before proceeding – refer to the fault location chart on page 22 if necessary.
Sounders can be tested by operating the SOUND ALARMS push button.
Three-wire Circuits (budget pcb only)
A typical connection for a three-wire circuit is shown in drg. no. S1599 (page 12); however, the following
modifications need to be made for the circuit to function correctly:
• The detector zone must be configured for Short = Fire, unless the circuit is compatible with
open and short circuit monitoring, i.e. detectors with an alarm impedance of > 100 Ohm and <
700 Ohm are fitted, and call points are fitted with a 470 Ohm series resistor. Refer to
Engineering Options.
• In these circumstances the sounder circuit is not monitored, therefore, a 4K7 Ohm resistor must
be fitted at the sounder circuit terminals.