Siemens MD-12HD, User Manual, Page: 12 / 74

11 Siemens Industry, Inc.
Meter Safety
Building Service Safety Requirements
(Load Center, etc.)
Equipment intended for use with field-installed current transformers that could be
installed in panel boards or switchgears shall observe the following:
Always open or disconnect circuit from power-distribution system (or service) of building
before installing or servicing current transformers.
A circuit breaker used as a disconnect must meet the requirements of IEC 60947-1 and
IEC 60947-3 (Clause 6.11.4.2)
Current transformers may not be installed in equipment where they exceed 75 percent
of the wiring space of any cross-sectional area within the equipment.
Current transformers may not be installed in an area where they block ventilation
openings.
Current transformers may not be installed in an area of breaker arc venting.
Not suitable for Class 2 wiring method nor intended for connection to Class 2
equipment.
Secure current transformer and route conductors so that they do not directly contact live
terminals or bus.
CTs shall be listed to UL2808
Meter Installation Safety Requirements
MD-xxHD meters must be installed in accordance with local electrical codes.
Use copper conductors only.
Connection to the mains terminals shall be made with 14 AWG minimum wire gauge.
External secondary inputs and outputs should be connected to devices meeting the
requirements of IEC 60950.
The following additional requirements apply for recognized board versions of the MD-
xxHD meter:
1. For use only with Listed Energy-monitoring Current Transformers.
2. Associated leads of the current transformers shall be maintained within the same overall
enclosure.
3. Unless the current transformers and its leads have been evaluated for REINFORCED
INSULATION, the leads must be segregated or insulated from different circuits.
4. The current transformers are intended for installation within the same enclosure as the
equipment. These may not be installed within switchgears and panel boards or similar.