Application
The digitally controlled MCM165x series monitors insulation level
between a non-grounded (IT) AC mains and its protective earth,
regardless of whether the mains is live or non-live (standby).
An AC or DC auxiliary voltage is required for the unit, if powered from a
separate source the network can also be monitored during standby
conditions. Only ONE MCM165x can be connected to each IT-system.
The
optional slave indicator give at a glance the clear safety message:
General
IDV MEASURING PRINCIPLE
Insulation is measured between the complete galvanically
interconnected AC network and its protective earth. The unit injects a
sequentially coded measuring signal into the monitored system. The
signal flows to ground via the path of the insulation fault, the level
of flow indicates the insulation resistance. The measuring accuracy is
not influenced by any normal kind of load attached to the AC network.
MEGGER SAFE
When auxiliary power is OFF the unit
input is automatically protected against "megger" test voltages up to
1.4kVDC, and incorrect measurements caused by the unit’s input
impedance are avoided.
OUTPUTS
The unit is supplied with an
isolated
analogue output proportional to insulation level. If output is
used for remote meter reading, we recommend 0-1mA for the slave
indicator.
SAFETY
When a voltage adapter (ARx or ANx) is used the signal to
terminals 4 and 6 on MCM165x is limited to a safe level,
avoiding any dangerous voltage exposure to personnel.
The MCM165x range is designed to comply with specification IMCA D 045
"Code of Practice for the Safe Use of Electricity Under Water" issued by
IMCA.
The unit meets IEC60092-504 and the relevant environmental and EMC
tests specified in IEC60068/60092 and IEC61000/60533 respectively, to
comply with the requirements of the major Classification Societies.
The Ultra-Reliability Concept (Paralleling of Transducers)
To obtain ultimate operational safety multiple MCM165x transducer inputs and outputs can be permanently paralleled.
At any time only ONE transducer should be enabled. The selected
transducer is activated by applying auxiliary power to unit. Accidental
enabling of more than one transducer will give distorted reading, but
will not harm the transducer.
MCM165HF
Scale range: 10kΩ - 500MΩ - ∞ (>2GΩ)
This unit is used for marine, offshore, seabed and down hole
installations.
Start of monitoring function is delayed when auxiliary
power is switched on (default 30 secs delay).
In this way false tripping
during power up, caused by initial charging of network spread
capacitance, is avoided. The start delay can be pre-programmed to allow
operation into any level of spread capacitance.
MCM165GF
Scale range: 500kΩ - 5GΩ - ∞ (>6GΩ)
This unit is used for marine, offshore, seabed and down hole
installations.
Start of monitoring function is delayed when auxiliary
power is switched on (default 30 secs delay).
In this way false tripping
during power up, caused by initial charging of network spread
capacitance, is avoided. The start delay can be pre-programmed to allow
operation into any level of spread capacitance.
Direct connection up to 690V line voltage.
Connection up to 25kV via
HV adaptor ARx or ANx series.
MCM165F
Scale range: 15MΩ - 10GΩ - ∞ (>12GΩ)
This unit is used for marine, offshore, seabed and down hole
installations.
Start of monitoring function is delayed when auxiliary
power is switched on (default 30 secs delay).
In this way false tripping
during power up, caused by initial charging of network spread
capacitance, is avoided. The start delay can be pre-programmed to allow
operation into any level of spread capacitance.
Direct connection up to 690V line voltage.
Connection up to 25kV via
HV adaptor ARx or ANx series.
