MultiTrode MultiSmart Installation & Operation Manual page 132

17.2.2.2 Inverting IRT (Pump Isolation) Dout
As configured the digital output is active whenever the IRT is active and the Isolation contactor must be open
during this time (i.e. the Contactor will be normally closed) so typically it will be necessary to invert the digital
output.
To Invert a digital output:
Navigate to:
•
Press the bottom button on the left-hand side marked Invert?
•
Press Save and Restart Now
•
17.2.3 IRT Inhibited
Case 1: Before performing a test, the IRT monitors the voltage on the IRT terminal. If it is above a
threshold (50V), the test is not performed.
Case 2: In addition, during the test, it monitors the load (current). If this is too high (as it will normally be if
the mains voltage is present, rather than an isolated motor), then the test is aborted. (This is done
in hardware, not in software).
In both of the above cases, the Last Test Status is updated, but the resistance is not (it retains the value of
the last successful test).
This means that a test is not normally performed when there is power to the motor, but Case 2 can occur,
which means that the high IRT voltage will attempt to drive, but the resistance won't be updated. If the IRT
attempts to drive a running motor, Case 2 is sufficient to protect MultiSmart and the very limited current
available means that driving the IRT will have no affect on the motor. The fact that the value is not updated
in either of these cases means that trends of the IRT value should be unaffected.
17.2.4 Manual Activation of the Insulation Resistance Test
An Insulation Resistance Test (IRT) can be manually activated. To perform an IRT:-
Press:
•
Press:
•
Press the left / right arrow keys at the bottom of the screen to highlight an IRT corresponding to a pump.
•
CAUTION: O
Press the Test Now button. The test will last for the time specified under Duration (default 60s)
•
CAUTION:
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MultiSmart Installation & Operation Manual
nce activated 1000 VDC will be present on the IRT terminals.
A test will be conducted for each press of the Test Now button.
or
MultiSmart_IO_Manual_A4_v2-22_R15.doc