Vigilohm IM20 and the injection wire

[AllanWang]

Dear all 

We are preparing a project for vessel insulation resistor monitoring system in which there are a few panels

to be monitored. Customer request to intall all the IRM devices in Main switchboard for centralizied monitor.  By doing that way, the long distance (the longest around 60m) injection wires have to be laid between main switchboard and individul panels. 

We select the device IM400 for MSB and IM20 for the other panels because the devices are marine class approved.  

Q1. Is the IM20 able to function properly with the long injection wire ( 2.5mm cable around 60m ) ?

Q2. Does it need a special cable ex screen type ( IM20 to be used in 230Vac DB panels and 24Vdc charger panels) ?