Installation Instructions

Document No. 553-131
Installation Instructions
August 16, 2013
Page 2 of 4 Siemens Industry, Inc.
Energy Management Applications
For energy management installations the service box
may be installed in any NEMA Type 1 enclosure if
the optional side wall kit is installed (PXA-SW192VA
or PXA-SW384VA). For more information, see PX
Series Service Box Sidewall Kit Installation
Instructions (553-135).
Optional: For TX-I/O Bus powered from multiple
service boxes, use UL Listed relay RIB2401C. For
more information, see manufacturer installation
instructions.
Instructions
WARNING:
This installation should only be done by
a qualified electrician.
WARNING:
Turn off AC power to the MEC
enclosure at a circuit breaker panel.
1. Be sure the AC power to the enclosure is OFF
at the circuit breaker panel.
2. Place the service box in the right side of the
enclosure. See Figure 1 and Figure 3.
3. Fasten the service box inside the enclosure with
the three locknuts (two on top and one on the
bottom).
4. Connect the green/yellow wire at the marked
earth ground lug on the enclosure.
CAUTION:
The green wire grounds the transformer
secondary neutral. This is required
whenever the primary side is greater
than 150 Vac, required by local code or
if used to power TX-I/O Modules.
5. If required connect the green wire at the marked
earth ground lug on the enclosure. Otherwise,
tape back the green wire terminal.
6. Do one of the following:
• 115 Vac models: Connect the AC hot (black
wire) and AC neutral (white wire) with wire
nuts.
• 230 Vac models: Screw the AC hot (black
wire) and AC neutral (white wire) to the
terminal block.
7. Fasten wire cover to the top of the service box.
For hardware without a TX-I/O Bus or TX-I/O Bus
not extending between enclosures, skip to step 8;
otherwise, choose Option 1 or Option 2 below:
Option 1: If powering both enclosures from a single
service box, continue with the following:
a. Connect a twisted pair of TX-I/O Bus cable from
the service box 24 Vac (~) and (⊥) terminals of
the Class 2 output connector to the
corresponding pins of TXS1.12F4, TXB1.P1, or
TXS1.EF4 in the other enclosure.
b. Connect the second twisted pair between the CS
and CD terminals of the TXS1.12F4, TXB1.P1,
or TXS1.EF4 in each enclosure.
Option 2: If using multiple service boxes to power a
TX-I/O Bus, continue with the following:
CAUTION:
DO NOT connect the 24 Vac (~)
terminals between the multiple service
boxes.
a. Do the steps for a single service box except do
not connect the 24 Vac (~) wire and CS wire.
b. Screw the relay onto the enclosure backplane.
c. Connect the relay coil 24 Vac terminal to the
service box 24 Vac (~) terminal.
d. Connect the relay coil neutral terminal to the
service box neutral (⊥) terminal.
e. Connect the CS wire entering and/or leaving
enclosure to the relay contact common terminal.
f. Connect the CS wire inside enclosure to the
relay contact normally open terminal (NO).
8. If present, fasten wires from the component
power connectors to connectors on the side of
the service box. See Figure 2 and Figure 4.
9. Restore power to the enclosure at the circuit
breaker panel.
The installation is now complete.