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7.2 Integration of digital signals (Low water level switch and Fire alarm device)
The FireSAFE unit has been specifically designed with the ability to power and relay digital
signals. The signals could be from any source but Grundfos suggest the following important
signals are used:
Digital input/output (DI2/D02) –Tank low water level switch device, to give a warning once
the water storage capacity has been reduced below the low level mark. The signal needs to be
present for more than sixty seconds before the controller activates the output.
Digital input/output (DI3/D03) – Water flow switch device, the only device allowable under
BS9251:2014 to indicate the presence of a fire and to give an alarm. Water flow switches
normally incorporates an adjustable delay option. This should be optimised to the site
conditions to prevent activating the Fire Alarm unnecessarily.
Consult the documentation supplied with your device.
The digital inputs are “wetted” with a 24 V DC voltage which can be applied to the digital
switching devices. Upon the changeover of the switch condition the digital inputs are relayed to
the volt free digital outputs for integration with an Alarm Control panel, Siren or other device.
The “wetted” inputs supplied by the FireSAFE unit remove the need to supply the signalling
device with power from another source. The inputs are optically coupled to the outputs and
hence voltage/current isolated between each other.
Neither Digital input inhibits the FireSAFE system from operating.
Further details in Electrical Installation section
7.3 Mains power monitoring / Controller internal fuse monitoring
On the application of mains electrical power the Power LED on the controller front panel
illuminates and the Fault relay (D01) to moves to its healthy position.
Upon failure of the mains power or the controllers internal fuse the LED extinguishes, the Fault
relay moves to its unhealthy positon and after more than 2 hours without power the internal
buzzer activates for 1 second every 30 minutes. This will continue until the Test/Reset button
is pressed. Buzzer becomes active again at next weekly test.
7.4 Semi-automatic learning of the pump condition
The FireSAFE controller is factory set to the pump full load current (FLC), and it can be reset in
the field following a change to the pump. Follow the service mode instructions in section 7.1.
This should be done against a closed valve system pressurised condition.
Summary of Contents for 97931710
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