Engineering Documentation

Table Of Contents
Appendix A Discontinued Products
Modular Equipment Controller (MEC) and Point Expansion Module (PXM)
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125-3002
NOTE:
UL-recognized wire (labeled with a backwards “RU”) is not field-installable. Use only
UL-listed wire.
For analog inputs, termination for shield is provided, if required. Termination for
shield is not provided for digital inputs. For more information, see the wiring
diagrams.
Power Source Requirements
Power Source Requirements for MEC.
Product Input Voltage Line Frequency Maximum Power
1,2
MEC 24 Vac 50/60 Hz 35 VA
MEC with FLN 24 Vac 50/60 Hz 50 VA
L model MEC 24 Vac 50/60 Hz 50 VA
MEC Digital Point Block, 4 DI, 4 DO 24 Vac 50/60 Hz 14 VA
MEC Digital Point Block, 8 DI, 4 DO 24 Vac 50/60 Hz 18 VA
MEC Analog Point Block, 4 AI, 4 AO 24 Vac 50/60 Hz 20 VA
MEC Analog Point Block, 8 AI 24 Vac 50/60 Hz 18 VA
Point Expansion Module 24 Vac 50/60 Hz 18 VA
PX Series Service Box – 192 VA 192 VA 50/60 Hz 200 VA
3
PX Series Service Box – 384 VA 384 VA 50/60 Hz 175 VA
1)
The 24V wiring is Class 2. It draws less than 50 watts of power. AC power uses Class 1 wire.
2)
An external connection is provided for power at 24 Vdc at 50 mA per termination (200 mA maximum all terminations) for
external sensors.
3)
Service outlets are restricted to only continuously power network devices.
Analog Input Powered Devices
Approved sensors drawing less than 25 mA can be powered by the MEC analog input
(AI) connections. Sensors requiring more power must be powered by an external
source. The external source can be connected to the same AC line as the MEC power
supply as long as it is only used to power low voltage devices (less than 30 volts).
Analog Output Powered Devices
The PX Series Service Box provides a 24 Vac 100 VA total power source to any
auxiliary device via a two-wire connection (L, N).
Powering Options
One of the options for powering the MEC, point blocks, and 24V devices is the PX
Series Service Box.
See PX Series Service Box in this chapter for more information.