Installation Instructions

ManualsBrandsSiemens ManualsBuilding automationAPOGEE Wiring Guidelines for Field Panels and Equipment Controllers

Document No. 553-131

August 16, 2013

PX Series

Service Box Assemblies

Siemens Industry, Inc. 553-131 (CA) Page 1 of 4

Product Description

The PX Series Service Box Assemblies transform

115 Vac or 230 Vac to 24 Vac that power HVAC

control components. The 192 VA service boxes

mount directly inside a 19-inch or 34-inch PX Series

Enclosure or as a replacement in older MEC

Enclosures. The 384 VA service boxes provide

additional power for larger systems and mount only

in the 34 inch PX Series Enclosure. The service

boxes are Smoke Control and Energy Management

listed when installed per this instruction.

The service box assemblies consist of:

− Chassis for mounting inside enclosure

− Transformer for converting either 115 Vac

or 230 Vac to 24 Vac sized for either 192 VA

or 384 VA

− ON/OFF Circuit breaker for transformer

− Two Class 1 power limited 24 Vac outputs

including one terminal for earth ground for

use inside enclosure only

− One Class 2 output with circuit breaker to

distribute up to 96 VA for use outside the

enclosure

− Duplex Service Outlet (115 Vac models

only)

− Wire cover for field connections

Product Numbers

PXA-SB115V192VA Service Box 115V, 24 Vac,

50/60 Hz, 192 VA

PXA-SB115V384VA Service Box 115V, 24 Vac,

50/60 Hz, 384 VA

PXA-SB230V192VA Service Box 230V, 24 Vac,

50/60 Hz, 192 VA

PXA-SB230V384VA Service Box 230V, 24 Vac,

50/60 Hz, 384 VA

Warning/Caution Notations

WARNING:

Personal injury/loss of life may

occur if you do not perform a

procedure as specified.

CAUTION:

Equipment damage or loss of

data may occur if you do not

perform a procedure as

specified.

Required Tools and Materials

• Medium Phillips screwdriver

• 11/32-inch nut driver

• 7/16-inch nut driver

Expected Installation Time

15 Minutes

Prerequisites

− Enclosure(s) installed.

− AC power brought to enclosure(s) and

power turned OFF at the circuit breaker.

− If using optional TX-I/O Bus (not available

on all hardware), it is pulled between

enclosures using single 2 twisted pair (TP)

or two 1 TP wire tied together. See TX-I/O

Bus steps for maximum length by wire

gauge.

Smoke Control Application

Requirements

UL864 and NFPA92A compliant installations require

the 115V or 230V PX Series Service Box Assembly

installed inside the 19-inch or 34-inch PX Series

Enclosure Assembly (PXA-ENC19 or PXA-ENC34).

For more information, see PX Series Enclosure

Assemblies Installation Instructions (553-130).

For smoke control installations, the 24 Vac Actuator

Output is a supplementary circuit intended for

general HVAC equipment only. It can not power

smoke control devices.

Optional: See the Field Purchasing Guide for

ordering the relay required for Smoke Control listing

if a TX-I/O Bus is powered from multiple service

boxes. (TX-I/O Bus not available on all hardware.)

RIB2401C UL864 Listed Relay, SPDT 24 Vac 10A

Summary of content (4 pages)

PAGE 1
Installation Instructions Document No. 553-131 August 16, 2013 PX Series Service Box Assemblies Product Description The PX Series Service Box Assemblies transform 115 Vac or 230 Vac to 24 Vac that power HVAC control components. The 192 VA service boxes mount directly inside a 19-inch or 34-inch PX Series Enclosure or as a replacement in older MEC Enclosures. The 384 VA service boxes provide additional power for larger systems and mount only in the 34 inch PX Series Enclosure.
PAGE 2
Document No. 553-131 Installation Instructions August 16, 2013 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). 7. Fasten wire cover to the top of the service box.
PAGE 3
Document No. 553-131 Installation Instructions August 16, 2013 Figure 1. Placement of the 384 VA Service Box in a 34 inch PX Series Enclosure. 1 Figure 2. 384 VA Service Box Connections . 1. 384VA model connectors will fit one 12 gauge and one 14 gauge wire or three 14 gauge or smaller wires. Siemens Industry, Inc.
PAGE 4
Document No. 553-131 Installation Instructions August 16, 2013 Figure 3. Placement of the 192 VA Service Box in a 19 inch PX Series Enclosure. 2 Figure 4. 192 VA Service Box Connections . 2. 192VA model connectors will fit one 12 gauge wire, one 14 and one 16 gauge wire or three 16 gauge or smaller wires. Information in this publication is based on current specifications believed correct at the time of publication. The right is reserved to make changes as design improvements are introduced.