23
TGH1361en/11.2009
4. Connection
4.1 Wiring
Connect the terminals A1/+ and A2/- to the supply voltage U
S
in accordance
with IEC 60364-4-43. The connections to the supply voltage shall be provid-
ed with protective devices to afford protection in the event of a short circuit
(a 6 A fuse is recommended).
Devices for protection against short-circuit in conformity with IEC 60364-4-
43 for the IT system coupling L1/L2 can be omitted if the wiring is carried
out in such a manner as to reduce the risk of a short-circuit to a minimum (a
short-circuit-proof and earth-fault-proof wiring is recommended).
Only one A-ISOMETER® may be connected to an external TEST or RESET
button. A galvanic parallel connection of several TEST and RESET inputs for
collective testing of A-ISOMETER®s is not permitted.
External coupling devices connected via the terminal AK cannot be switched
off via the internal coupling relays. If no coupling device is used, the terminal
AK remains free.