![background image](http://html1.mh-extra.com/html/te-connectivity/m242-05-series/m242-05-series_installation-instructions_3936908001.webp)
CI-3K472001 Project 2215 Rev.0 04/03/13
Installation Instructions
M series Analogue DIN Panel Meters
M242-05*, M242-15*, M244-13*, M242-41*
M243-05*, M243-15*, M244-21*, M243-41*
M244-05*, M244-15*, M244-31*, M244-41*
Introduction
This product range includes a wide range of functions,
including AC Ammeters and maximum demand meters; AC
Voltmeters; DC Ammeters and milliammeters; DC
Voltmeters and millivoltmeters; Elapsed time meters;
Frequency meters; AC wattmeters and var meters and
Power factor meters.
Marking and ratings
Body side labels show function, electrical rating, and
connection diagram, where there are more than two
terminals on the unit. For two terminal units, the terminals
are connected directly across the input to be measured.
Terminal numbers are moulded into the base adjacent to
each terminal stud and corresponding numbers appear on
the connection diagram. Note that the electrical rating may
differ from the dial scale marking, and the unit side label is
definitive.
These meters are intended for a rated temperature range, is
-20/+60 deg C and up to 80% relative humidity, and only for
indoor use at an altitude of less than 2000m. Shock
maximum level is 30g.
Installation
The meter should be installed in line with the requirements
of the local electrical code. It should be installed in a dry
position, not in direct sunlight and where the ambient
temperature is reasonably stable and within ratings above.
These units are only for built in use and with terminals
inaccessible to users after installation and should be
mounted to a DIN panel cut-out up to a maximum thickness
of 5 mm. Mounting is by 2 opposed corner clamps. It may
be convenient to use a 7mm screwdriver style nut driver to
engage the barrel nuts on those models with plastic nuts,
particularly when starting the thread, but great care must be
taken not to over tighten. It is very easy to cause damage
with excessive torque when using a nut driver, so final
tightening should be performed with finger pressure only.
Fusing and connections
External voltage transformers and current transformers may
be used where appropriate to extend the range, provided
that the ratings marked on the side label are not exceeded
at point of connection to meter. These products are
designed for permanently connected use, normal condition
measurement category III, pollution degree 2 (e.g. non
ventilated panels or ventilated panels with filters, without
condensation occurring), basic insulation, for rated voltage.
Connection diagrams shown on the unit side label should
be carefully followed to ensure correct polarity and phase
rotation where applicable. Terminals are intended for use
with insulated ring lugs. Ensure a minimum spacing of
5.5mm (0.21”) between uninsulated parts of adjacent ring
lugs. Tighten terminal screws to 2Nm (1.5 ft/Lb) only.
These products do not have internal fuses therefore
external fuses
must
be used for safety protection under
fault conditions. Voltage input lines where required must be
fused with a quick blow fuse 1A maximum. Auxiliary supply
lines, where required must be fused with a slow blow fuse
rated 1A maximum. Current metering circuits directly
connected in line with the load must be fused at the rated
current for the meter. Where fitted, current transformer (CT)
secondaries must be connected to protective earth in
accordance with local regulations. Do not fuse CT circuits.
The equipment into which this meter is installed must have
a clearly marked adjacent means of isolating the supply
voltage to permit safe access for subsequent maintenance.
Ensure supply circuits are rated for meter VA: >4.5VA
Choice of associated components
Choose fuses of a voltage rating equal to or exceeding the
rated voltage of the circuit into which the meter is connected
and of a type and with a breaking capacity appropriate to
the supply to which the fuse is connected. Connection
wires and ring lugs should be rated for at least 1A for
voltage and auxiliary lines and to at least the rated current
for current measuring circuits. Additionally, wires for DC
current meters rated over 50mA must be rated at 75 deg C
or greater. Ensure cables and ring lugs have a voltage
insulation rating equal to or greater than the rated voltage of
the circuit to which they are connected.
CT cable impedance should ensure that CT VA rating is not
exceeded and it’s accuracy impaired.
Cleaning and maintenance
As required, wipe the front face with a damp cloth, ensuring
that no moisture enters the unit or penetrates behind the
mounting panel. No maintenance is required beyond
periodically checking the mechanical zero of the meter as
described overleaf in “commissioning”, if necessary
removing any accumulations of dust or other foreign matter
from the terminal area and ensuring that connections
remain tight.
Warnings
During normal operation, voltages hazardous to life may be
present at some of the terminals of this unit.
These instructions contain important safety information: Read
before starting installation or servicing of the equipment
Installation and maintenance should be performed only by
qualified, properly trained personnel' abiding by local
regulations.
Ensure all supplies are de-energised before attempting
connection or other procedures.
Never open circuit the secondary winding of an energised
current transformer.
If this equipment is used in a manner not specified by the
manufacturer, protection provided by the equipment may be
impaired.
Measurement categories 600V CAT III.
Caution: Risk of
Electric Shock