Specialty Concepts DM3 - Manual (Page 6)

INSTALLATION INSTRUCTIONS
1. LOCATE A SUITABLE LOCATION. Page 12. This location must be protected from moisture, dust, dirt, and
bugs. The DM3 MUST NOT be mounted out-of-doors unless it is installed in a suitable, COMPLETELY SEALED
enclosure (available from your dealer). The DM3 may be mounted where other system components (batteries,
inverters, etc.) are located or it may be mounted in a remote location many hundreds of feet from other equipment.
2. DECIDE ON WHAT WILL BE MEASURED. P age 13. You will probably want to monitor AT LEAST the
battery voltage and the charging current from the solar panels. You might want to ALSO monitor load current and
load voltage. Measuring battery voltage will automatically provide operating power to the DM3.
3. DECIDE ON INTERNAL OR EXTERNAL SHUNT(S). P age 13. If any current that you decide to measure is
less than 30 amps, AND you can properly run heavy enough wires to carry this current to the DM3, then it would be
easiest to use the internal shunt. If you are measuring more than 30 amps, or if you cannot run heavy enough wire to
the DM3, then you must use an external shunt. If you are going to measure 2 currents, you MUST use an external
shunt for the second current.
DO NOT PERFORM THE FOLLOWING PROCEDURE UNLESS YOU ARE SURE THAT YOU WILL BE USING AN
EXTERNAL SHUNT FOR CURRENT 1. DO NOT PERFORM THE PROCEDURE WITH ANY POWER APPLIED
TO THE UNIT.
To use an external shunt for Current 1, you must cut out the internal shunt. To do so, use a heavy-duty wire cutter with a
narrow point to cut the internal shunt. The shunt is the gold-colored loop of wire between the DM3 chassis and circuit
board, just below the CURRENT 1 terminal block.
4. MOUNT THE DM3. Page 12. You have 2 basic choices; surface or flush mount. For surface mount (which is the
easiest method), you will need a small enclosure. The enclosure is mounted to a wall and the DM3 is then mounted
into the enclosure. To flush mount the unit (this is more difficult, but looks better), use the template on page 16 of this
manual for further flush-mount details. You will have to cut a hole in your wall and run wires in the wall. REFER TO
THE APPROPRIATE SECTION OF THE NATIONAL ELECTRICAL CODE FOR PROPER AND SAFE METHODS
FOR INSTALLATION. IF IN DOUBT ABOUT INSTALLATION, SEEK ASSISTANCE FROM A QUALIFIED
EXPERT.
5. SET OPTIONS. Page 10. The DM3 comes factory programmed for a 12 volt system as follows:
HI ALARM: 15.5 volts
LO ALARM: 11.5 volts
CURRENT 1 DECIMAL POINT: on (Does not need to be changed for ext. shunts less than or equal to 100 amps).
CURRENT 2 DECIMAL POINT: on (Does not need to be changed for ext. shunts less than or equal to 100 amps).
ALARM PROGRAMMING: off
AUX. INPUT: set for normal voltage reading with respect to system ground.
If these program options suit your needs, you do not need to alter any settings and you may proceed with the
installation. You may change these settings at any time as you may require.
6. WIRE DM3. P age 13. For appropriate wire sizes, refer to Page 6.
NOTE: If you are using the optional enclosure on the back of the DM3, you may find it easier to wire the unit if the
knock-outs in the box are placed towards the top of the unit. When wiring the DM3, run the wires through these
knock-outs (and through a cable clamp) and then down over the label on the back of the DM3 and then into the back
of the terminal blocks.
• BATT+ and BATT-.You must connect the BATT+ and BATT- positions on the DM3 to a source of DC voltage. In a
solar system, this is normally the batteries. It is recommended that 18 gauge wire be used for typical installations. If
your DM3 is located more than 100 feet from the batteries, then a larger size wire should be used. Using wire that is too
small will cause no damage and is not dangerous. It will, however, result in slightly inaccurate voltage readings.
• AUX+ and AUX-. Connect these 2 positions to a second source of voltage that you wish to monitor. Some examples
are: a second set of batteries, the voltage from the solar panels, the voltage at a load, or any other DC voltage in the
system. Any wire size may be used. This input can also be used as a digital meter for general system testing. To
measure a third current with an external shunt, remove the AUX. SCALE SELECT jumper and connect the external
shunt to the AUX. inputs.
• CURR1+ and CURR1-. Use this position to measure any current (up to 30 amps) using the internal shunt or any current
with an external shunt. When using the internal shunt, you must use wire of sufficient size to carry the measured
current with a minimum of loss. With an external shunt, any size wire may be used to connect the shunt to the DM3.
• CURR2+ and CURR2-. Use this position to measure any current using an external shunt. When connecting a shunt to
this input, first remove the jumper shorting the screw terminals together. This jumper is no longer needed if the shunt
remains wired to the DM3.
7. TEST DM3. With power applied to the DM3, you should be able to measure the battery voltage by placing the
Measurement Selection Knob to the first position. If you have shunts (internal or external) installed in the system to
measure current, you should be able to measure these currents by turning the knob to the appropriate position. If you
encounter problems with the DM3, refer to the trouble-shooting section, page 9.
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