NOVAR 300 Operation & Maintenance Manual NOVAR_CM
Page 22 of 29
4. FAULT FINDING AND TEST PROCEDURES
4.1 FAULT FINDING
When power is first applied to a NOVAR it examines both its own circuitry and the system
into which it has been connected. If it finds any faults in either situation, it will signify this as
follows.
4.1.1 Connection error
See section 3.6
4.1.2 Low system voltage
If the system voltage is below nominal working range, the NOVAR will perform a voltage
reset. A line of four dashes will appear across the centre of the display for a few seconds
and the unit will then reset.
4.1.3 System current errors
If the system current is below 10 percent of nominal, the NOVAR will display a line of
dashes across the bottom of the display instead of cos phi. Apart from this, the unit will
continue to operate normally. This will also be the display if the CT circuit is not connected.
If the system current is above 120 percent of nominal, the NOVAR will display ‘A-HI’.
4.1.4 Incompatible settings
There are various situations where the NOVAR will appear not to be working properly.
These are, in fact, caused by incompatibilities in DIL switch settings, c/k and/or target cos
phi settings or an incomplete knowledge of how a particular NOVAR is programmed:
4.1.4.1 If sequence 4 or 5 is selected, it will not be possible under any circumstances to set
the limit above 9. The same applies for sequences 6 and 7, the appropriate limits being 7
and 6 respectively.
4.1.4.2 If the limit is set to 1 then the sequence will automatically be set to 0 as any other
sequence would be meaningless. Similarly, if the limit is set to 2 then the sequence can not
be set higher than 2.
4.1.4.3 The NOVAR power factor controller is a device designed to reduce the lagging vars
present in a system. Because of this, the system power factor is not necessarily a good
measure of whether the unit should be changing the state of its outputs. As an example, it is
possible to have an extremely poor power factor with low current as well. In this case,
although the power factor is poor, the actual reactive power present may still be very low.
4.1.5 Factory programmed settings
There are two factors which are programmed into the NOVAR during test. The NOVAR is
only able to operate as indicated on its label in regards to these:
- rotational or linear switching (test assist mode always works rotationally)
- manual mode automatic exit enabled or disabled
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