Font, your suggestion about the use of a dedicated plug is a good one.
However, if you sort out the issue of the in-rush current either with a transformer designed to reduce this or, alternatively, replace the CB in the panel (at the source of the IPS power–circuits) relating to the wall-socket where your stack will be connected, with a dedicated less sensitive CB (a much cheaper option if technically agreed to by your hospital electrical engineers), then you will not need to fit a dedicated plug and so allowing the equipment to still leave the IPS area if need be.
John, the contributions from this forum seem to show categorically that in the latest IPS system requirements, both in-rush currents and unexpected DC currents are candidates for mischief-making with the detector circuits. If your displays are giving a dc current into the mains/earth line for whatever technical reason (Meg resistors to ground etc!), then If your IPS system does not use say a (high-frequency?) pulsed-dc to monitor the insulation-to-earth of the mains wires, you will have to isolate this with a transformer to block the dc component. Blocking the external pathway for the display’s dc component will in no way affect the well-being of the display itself but if not blocked is obviously a no-go for safety monitoring in your area. As to in-rush currents, see what Font comes up with through his investigations and that should reduce/eliminate completely this nuisance-factor to the detector circuits and, of course, still allow the equipment to be used outside the IPS area. If you choose a low in-rush type of transformer this will equally prevent CBs potentially tripping in non-isolated areas too in which you might be using your display. Could be a case of “killing two birds (these two issues) with the one stone (ie the transformer)”
Now to what value the “leakage-setting” control (for your sensors) should be set to (as I am assuming it is this setting that you are concerned about and not a setting for the in-rush detection circuits – not that I would be expecting to hear that there was one for this!). Well if the manufacturer has provided you with no information for guidance then the conventional IPS leakage trip is generally set to trip around 2 to 5 milliamps. In lieu of any other value, you can quite happily use this. If your setting-control has an ohms scale then this current-equivalent value would equate (for the low current-trip point of 2mA) to a reading of 115 Kilo-ohms with your mains voltage of 230, and an ohm’s value of 46K for the higher 5mA trip-point For anyone with a mains voltage of 115 volts, the corresponding current readings are halved, of course
With regards to how to set it up, “no worries mate”. Just set the trip to a value within the above range (normally a starting point of 2mA /115K will be fine). As to equipment being connected to wall-sockets in the area when you set this up, you do not need to take this into account at all. However, just remember that the way an IPS works is that the more equipment that is added to the system (ie plugged into the wall sockets in the area at any one time, the lower the overall impedance of the system will be (reduction in impedance being provided by the aggregate of all the equipments resistances and reactances to earth). This means that if, in the rare event, you have so much equipment in the room that the lower trip-point (2mA/115K) is almost reached, when you add another piece of equipment the alarm may sound. Temporarily turn up the control setting to compensate. Obviously if turning it up does not cancel the alarm then you know you have a real over-load from a piece of equipment or just too much equipment connected in that area. Note too that this detection circuit is not protection against our “earth leakage currents”. An IPS is not capable of providing such protection.
