MTRA-FSP Installation & Operation Manual
00242600-MTRA-FSP_Manual.doc
Page 13 of 16
6.2.2
Thermal Backup (BU) Input
The MTRA-FSP can be used as a backup pump control device for the
MultiSmart Pump Controller and RTU. When used as a backup, the Thermal
sensor is wired into the Thermal input, and the MultiSmart Thermal input is
wired into the MTRA-FSP Thermal BU input.
6.2.3
Failsafe Probe Alarm Input
MultiTrode probes can be sold with an extra connection to the top sensor for
failsafe detection. This is used to detect if the probe sensor cable has broken
by checking there is a circuit. If the cable is broken, there will be no circuit back
to the failsafe input and an alarm will be raised.
When a failsafe alarm occurs the Probe LED flashes and the Failsafe Alarm
output contacts are activated. Also the pump contacts will be deactivated so
the pump cannot run until the fault condition is removed.
NOTE:
If a non-failsafe probe is used then a jumper must be connected
between the Alarm Probe and Failsafe Inputs to prevent Probe
Fault Alarms occurring.
NOTE:
The failsafe probe input must be connected to the highest probe in
the system if used.
6.2.4
Assumed Probe Faults
If a High Level, or High Alarm input is activated and the Low Level probe is
deactivated, then the relay assumes the Low Level probe is faulty.
This condition is called an “Assumed Probe Fault”. The relay indicates this
condition by flashing the Level Alarm LED - single pulse on, 3s off.
The relay will also change its pumping behaviour to a timed method until the
fault condition is no longer present. See the assumed probe fault notes in
Sections 5.1 and 5.2.
