13
NT311 ETH
POWER SUPPLY
The NT311 control can be supplied by 85 to 260 Vac-Vdc, 50/60 Hz irrespectively of polarity in Vdc (terminals 40 - 42).
This particularity is obtained thanks to the use of a tested power supply, of new conception and realisation, which frees
the installer from any uncertainty regarding the correct Vac or Vdc power supply.
The earthing cable must always be connected to terminal 41.
If an existing control unit must be replaced with a new one, to guarantee its correct and safe operation, the
sensor/relay/supply connecting terminals must be replaced with the new terminals supplied.
ALARMS
Carry out the electrical connections on the removable terminal blocks only after disconnecting them from the unit.
When the control unit is in one of the following modes, it does not perform any monitoring, moreover the relays will all be
disabled, the fault contact switches and the fault LED will flash.
•
Programming viewing display.
•
PRG programming.
•
Relay test.
The ALARM, FAN and HEATER relays only switch when the set limits are exceeded, see paragraph on the monitored
value diagnostics.
The FAULT (fault) contact, programmed in active failsafe mode (default YES), opens when the appliance is powered, only
if during the access phase the control unit does not detect anomalies, and keeps the switching until when one of the
following events occurs:
•
Data memory fault (Ech message).
•
TEC sensor fault -°C -dSt - rH.
•
Insufficient supply voltage.
•
During the power on reset after programming (PRG), displaying of the data (VIS) and relay test.
FAULT AND RESET MESSAGE SEQUENCE
Find below the sequence of fault messages and RESET function condition.
1) ECH
2) ERR TEC
3) ERR °C
4) ERR dSt
5) ERR rH
FAULT FAILSAFE
By setting YES (Fail safe), contact 9-11 is positioned as normally open and switches (closed) when a fault condition is
identified. Setting NO (NO Fail safe) the contact 10-11 is positioned as normally closed and switches (open) when a fault
condition is identified.
If the fail safe function is disabled on the fault contact, the control unit will no longer be able to signal the fault due to power
failure.
NOTE: always disconnect the unit before performing any electrical connections.
FAULT 10-11 NC: ALARM FAULT OR POWER OFF
FAULT 10-11 NO: POWER ON OR NO FAULT
FAULT CONTACT OPERATION
eeprom fault
sensor communication fault
sensor fault
sensor fault
sensor fault
erasable message
non-resettable condition
non-resettable condition
non-resettable condition
non-resettable condition
To protect the control unit against line overvoltages, the PT-73-220 electronic arrester, designed by TECSYSTEM
S.r.l. for this specific purpose, is recommended. Alternatively, it is advisable to use 110 V AC supply voltages or,
even better, 110 VDC.
