User’s Guide | TOTEM 10 - TOTEM 20
16 of 30
unit to turn off thus restoring safety conditions. The second threshold value is set to
50% of LEL, exceeding of this values is reported directly to the safety relay that is
actuated even in the event of PLC malfunctioning, closing the gas supply valve and
turning the unit off.The electrical switchboard terminal block includes a contact for
connection to the natural gas solenoid of the central heating system. In the event of
a gas leak, the relay opens this circuit, too, by commanding valve closure.
Exhaust Gas Emission Hazard, Lack of Water Flow Hazard, Timing variation
Hazard
The above mentioned occurrences can pose a danger by causing an increase in
temperature which may cause some of the unit’s parts to become hot thus putting
the operator at risk of burns, or by causing a discharge of exhaust gases that
upstream of the catalyst feature a high carbon monoxide content.
These anomalies can be detected by a safety thermostat fitted inside the unit’s
enclosure and calibrated to actuate the emergency relay upon reaching 75°C, which
willl switch the unit off. This is a certified system guaranteeing high reliability even in
the event of a failure of all other control systems fitted onto the TOTEM.
Emergency Pushbutton
The Operator Panel features an emergency pushbutton that can be pressed in the
event of any risk situation. The emergency pushbutton actuates the emergency relay
that will switch the micro cogenerator off thus restoring safety.
In order to ensure proper functioning of the safety devices and, consequently,
Totem’s operation under fully safe conditions, the following requirements must
mandatorily be met upon installation:
-
The central heating system solenoid must be connected to the specially
devised terminal block located on the TOTEM electrical switchboard;
-
Proper room ventilation – at least 600 m
3
/h must be ensured or,
alternatively, enough windows must be provided in the room so as to
ensure an equivalent ventilation rate according to volumes, or a CO sensor
must be installed in the central heating system.
