EsiWelma Sensigas EW40, Инструкция по установке и эксплуатации

Страница: 30 / 96

Type / N.
Rev. Data Page Total pages
EW095.605 5 November 2010
30 96
EsiWelma
s.r.l.
A warm air heating system created with unit heaters spread throughout a building is
shown in Fig. 4.12. A gas shut-off valve and a methane gas detector is set up for each
unit heater.
Fig. 4.12 – Extended structure of the system (example)
If a detector warns of a gas leak, the assigned relay module energizes as follows:
•
in pre-alarm it commands a visual alert
•
in alarm threshold one it cuts off the gas valve relative to the unit heater controlled
•
if at least one detector exceeds the second alarm threshold the general gas valve is
closed.
4.5 Connections of the control unit to the system monitor
The UCE40... control unit can be connected to a monitoring system through the two
dedicated communication ports:
One RS232 Standard port for point-to-point connections, to a maximum distance of 10
meters
One RS422 Standard port for multidrop connections, to a maximum distance of 300
meters and a maximum number of ten control units.
the communication protocol is the Standard MODBUS

ASCII; the control units are
SLAVES, the monitor is MASTER
The type of port used and the communication speed can be set by user interface.
For more details on the protocol see the dedicated documentation.
Pr
Bus
Power supply (12 Vdc)
UPS
M
A
R
4
0
URG40.. URG40.. URG40..
URG40..
M M
M
A
R
4
0
M
A
R
4
0
M
A
R
4
0
M
M
Unit heater
General
Solenoid valve
Solenoid valve
1
Solenoid valve
2
Solenoid valve
3
Pr
Pr
1s
1s
1s
2s
M
Pr 1s
Unit heater
Unit heater
Unit heater
Solenoid valve
i