IOM FTI Iss.1
October 2018
Page 6 of 8
2.2
Electrical & Power Supply
THIS IS AN EXTRA-LOW VOLTAGE DEVICE, DO NOT CONNECT TO MAINS VOLTAGES OR
CONNECT MAINS VOLTAGES WITHIN THE BOX.
Power Supply and Battery
The SprinklerSense system requires a D.C. power supply connection within the range of 9 to 30 Volts. This
allows it to be supplied using proprietary battery backup systems of either 12 or 24V DC. The average power
consumption of the system including the SPDB30/90 and the FTI is circa 1.2Watts.
To provide battery backup to supply both the Flow switch and the FTI for a 72 hour period, use the following
capacity batteries:
For 12V systems, 7 Ah
For 24V systems, 5 Ah
The power supply connections should be connected to the FTI at J1 terminals 2 and 3, (12-24V and 0V).
J1 Terminal 1, Earth terminal should be connected to electrical earth.
FTI to Flow Switch
A 4-core cable should be used to connect the FTI directly to the flow switch unit, using J1 terminals 4 to 7 in the
FTI to terminals 1 to 4 in the flow switch. Connect V+ to V+, V- to V-, COMS+ to COMS+ and COMS- to
COMS-. Shown in wiring diagram below.
Relay Outputs
Connect the SPDB30/90 flow switch outputs as required, referring to the SPDB30/90 instructions.
The switch outputs from the FTI can also be connected if required. The Flow output switch consists of a
common connection (COM), a Normally Open contact (NO) and a Normally Closed contact (NC). The contacts
are in their Normal state during non-flow conditions. The output switches should be connected as required, in the
same way as traditional flow switch micro-switch outputs. The contact ratings of 24VDC and 500mA should not
be exceeded.
The ERROR output provides a relay contact switch which can be used to warn of possible failure of the flow
switch or of poor sprinkler pipe conditions which may adversely affect the function of the sprinkler system.
There is one ERROR output switch consisting of a Common connection (COM), a Normally Open contact (NO)
and a Normally Closed contact (NC). The contacts are in their normal state during the non-error condition.
