Accessories

Accessories are required depending on the type of installation on which the device is installed.

Accessories list

Accessory	Catalog number
Cardew C “250 V” surge limiter	50170
Cardew C “440 V” surge limiter	50171
Cardew C “660 V” surge limiter *	50172
Cardew C “1000 V” surge limiter *	50183
Cardew C base *	50169
ZX impedance	50159
IM400-1700 voltage adaptor *	IMD-IM400-1700
PHT1000 voltage adaptor *	50248
P1N ground adaptor	PHA6326700
Voltage transformer	See Note

NOTE:

P1N ground adaptor is applicable for IM400THRN.
For information regarding automatic and mobile insulation fault locating accessories, see Locating.

Voltage transformers must be selected appropriately depending on system voltage. Refer to the Schneider Electric Medium Voltage Transformer catalogue.

Cardew C surge limiter

Function	Cardew C is used if the insulation monitoring device is connected to the secondary connection of an MV/LV transformer (according to the rules and conventions that apply in the various countries). It protects the low-voltage (LV) installation against over voltage hazards. It is connected to the secondary connection of the transformer. Cardew C can be used on the following systems: U < 1000 V AC U < 300 V DC
Selection table	Un: Nominal Phase-to-Phase Voltage of AC System		Ui: Arcing Voltage	Type of Cardew C
	Accessible neutral	Not accessible neutral	Ui: Arcing Voltage	Type of Cardew C
	U ≤ 380 V	U ≤ 220 V	400 V < Ui ≤ 750 V	250 V
	380 V < U ≤ 660 V	220 V < U ≤ 380 V	700 V < Ui ≤ 1,100 V	440 V
	660 V < U ≤ 1,000 V	380 V < U ≤ 660 V	1,100 V < Ui ≤ 1,600 V	660 V
	1,000 V < U ≤ 1,560 V	660 V < U ≤ 1,000 V	1,600 V < Ui ≤ 2,400 V	1,000 V
Dimensions
Mounting	Cardew C mounted directly on busbars Mounting with plate-mounted base
Connection

ZX limiting impedance

Function	ZX limiting impedance enables you to create an installation with a high-impedance grounded neutral system (1500 Ω at 50 Hz). ZX limiting impedance remains connected during insulation fault locating at 2.5 Hz: 1500 Ω at 50 Hz 1 MΩ at 2.5 Hz The ZX impedance must be used on systems with U ≤ 500 Vac.
Dimensions
Mounting	On mounting plate
Connection

Voltage adaptor

The optional voltage/ground adaptors are:

IM400-1700
PHT1000
P1N

Function	The IM400-1700 and PHT1000 voltage adaptors can be used to connect a IMD to ungrounded systems higher than 480 V AC. The wire connecting IM400-1700 or P1N to IMD has to have the same voltage rating as the monitored network. The P1N ground adaptor must be connected with the system for the operation of IM400THRN. The compatibility of voltage adaptors with insulation fault location is as follows: The IM400-1700 and P1N voltage adaptors are not compatible with insulation fault location. The PHT1000 voltage adaptor is compatible with insulation fault location.
Dimensions	IM400-1700	PHT1000	P1N
Mounting	On DIN rail	On mounting plate	On mounting plate
Connection	Wiring diagram	Wiring diagram	Wiring diagram
	(1) Voltage adaptor connected to a phase (2) Voltage adaptor connected to neutral

S3 subassembly (retrofit)

Insulation alarm thresholds of the device has to be set higher than 2 kΩ to take into account internal impedance of the no longer commercialized S3 subassembly.