Protect PV.500 Operating Instructions
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The insulation test can only be started manually if an insulation
test is not already running at the time.
5.3.4 Insulation Monitoring in Partner Operation
In partner operation (see Chapter 5.5), both inverters are fitted with
the isometer.
Insulation measurement in single operation
In single operation, the two inverters behave like two individual
units. Insulation measurement is active in both inverters.
Insulation measurement in linked operation
In linked operation, the inverters are connected on the DC voltage
side. If both inverter isometers were to be active in this operating
mode, this would distort the measurement of the insulation re-
sistance. Therefore, in linked operation, the isometer of the invert-
er which is not active is switched off and its sensors are discon-
nected from the DC voltage. Now only one isometer is active and
the measurement of the insulation resistance is correct.
5.3.5 Insulation Monitoring Parameters
All parameters are only relevant for operation with thin-film solar
cells.
Insulation test time:
The analogue and digital signals from the isometer are evaluated
during this time.
Delay for insulation test following shutdown of K21 (earthing
of PV cells):
Once the earthing has been disconnected, this time must elapse
before insulation measurement can start.
Delay for shutdown of K21 in night operation:
Once sequence control has switched to the “Night” status, this time
must elapse before earthing is removed with contactor K21.
Minimum time in maintenance mode:
If maintenance mode has been activated, the earthing is discon-
nected and remains so for at least this time.
