1.0 Pre-Installation Information (Continued)
Internal Electronic Assemblies
The unit is comprised of two major
subassembly boards, Main Power
Board and Display Board. All circuit
cards are mounted inside a
NEMA 12 (standard) or
NEMA 4X (optional) enclosure.
NOTE: Units are supplied in a NEMA 12 metal enclosure suitable for indoor
applications only. Units supplied in the optional NEMA 4X fi berglass enclosure
are suitable for either indoor or outdoor applications, within the defi ned specifi ca-
tions. Refer to Section 12.0 for a defi nition of suitable environmental conditions
for indoor and outdoor units.
Main Power Board
Connections to this board include the MAINS Input Voltage, Current Sensors,
external IDR interface and Isolated Pulse Output.
The MAINS input terminals are covered with a protective clear shield for safety
purposes. The current sensor assemblies interface to either TB1 (standard con-
fi guration) or to three header connectors, TB2, TB3 and TB4 (MI confi guration).
Each header connector input corresponds to an input voltage phase, so care
must be taken to ensure each current sensor is connected to the correct input
header. TB4 is not to be used as an input on the Class 1000 meter.
(Standard Confi g.)
(Optional MI
Confi g.)
Display Board
The display board connects to the main power board via a fl ex-ribbon cable and
the board is mounted on the inside of the enclosure door. The display board LCD
readout indicates the cumulative kWh and instantaneous kW value. Additionally,
errors such as low battery conditions or sensor error conditions are displayed.
Page 2
Main Power Board Display Board
(Showing ST Confi g)