Installation Requirements; Maintenance - Siemens ET 200M Manual

16-Channel, 24 VDC Power Supply MTA
Power is supplied via the power connector marked L+A, MA, and L+B, MB. Each
has a green LED to indicate the presence of voltage over 15 VDC. In the case of
polarity reversal of the power supply, the LEDs will illuminate red. The LEDs are
marked A POWER and B POWER.
Incoming power from A and B is diode OR'd to provide the MTA from either power
source. The output from the dual diode is used to supply the 16 outputs of the
MTA.
One green LED per output signals the power availability for this channel.
An onboard Power Monitor System (PMS) is used to provide an isolated dry
contact when redundant power is supplied to MTAs. Only when power is supplied
to both power inputs the output contacts 1 and 2 are closed. The Power Monitor
System is designed to detect only the presence or absence of power. It is not
designed to detect supply voltage which is outside the specification threshold.
An onboard Short Circuit Detection (SCD) is used to provide an isolated dry
contact in case one or more outputs will be short circuited. For a few seconds after
applying or removing the short circuit, the dry contact may toggle before providing
a stable ON or OFF status.
Field Terminals, Power+ (PWR+), Ground (Mx), and Shield (SHx), connect to the
field devices. PWRx provides the transducer supply current. Mx is the transducer
power return.
! Caution
The heat sink can be over 100 °C. Avoid contact during servicing.
22.4

Installation Requirements

See Section 2, Installation, before performing any installation and observe all
warnings
22.5

Maintenance

See Section 3, Maintenance, before performing any maintenance and observe all
warnings
Under normal operation, the A/B Power LEDs are illuminated green. If an A/B
Power LED is illuminated red (or off), check the power supply to the MTA.
Under normal operation the 16 LEDs on the outputs are illuminated green. If one or
more LEDs are off, check the cabling or load for a short circuit.
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Marshalled Termination Assemblies for ET200M Remote I/O Modules
A5E00482820-12