Specialty Concepts DM3 - Manual (Page 9)

SPECIFICATIONS
PARAMETER VALUE
Operating voltage range............................................................. 9 volts to 65 volts continuous, 85 volts for 1 minute.
Current measurement, internal shunt
(NOTE 1)
............................ 30 amps
Current measurement, external shunt
(NOTE 2)
............................ Up to 999 amps
Operating temperature range..................................................... 32° F to 122° F (0° C to 50° C)
Current consumption
1. No options installed, no alarms activated @12 volts: 13ma @48 volts: 17ma
2. No options installed, one alarm activated @12 volts: 17ma @48 volts: 21ma
Accuracy
1. DC voltage.................................................. +/- 1%
2. DC current................................................... +/- 2%
Alarm settings............................................................................. User adjustable over operating voltage range. Factory
set to: Lo Alarm - 11.5 v, Hi Alarm - 15.5 v
Alarm delay.................................................................................. Up to 5 seconds
Alarm calibration readout accuracy............................................ +/- 2%
Alarm hysterisis.......................................................................... Approximately 3% of setting
Optional alarm relay contact ratings........................................... Up to 28 volts: 1 amp. From 28 to 65 volts: 100ma.
Non-inductive load.
Size
1. No options, no enclosure............................... 7.5 in. W X 4.2 in. H X 2.5 in. D
2. With enclosure.............................................. 7.5 in. W X 4.2 in. H X 3.0 in. D
NOTES:
1. Internal shunt can be removed to allow current measurements with an external shunt.
2. Use 100 amp/100 mv , 500 amp/50mv, or 1000 amp/100mv shunts.
FREQUENTLY ASKED QUESTIONS
1. WHY DO I NEED EXTERNAL SHUNTS ? - The internal shunt on the DM3 can only handle 30 amps, so if you want
to measure a current greater than 30 amps, you must use an external shunt. This external shunt would normally be
located near where the current is flowing so that only the small wires carrying the shunt’s signal need be run to the
DM3. Also, if you wish to measure a second current, you must use an external shunt.
2. CAN I DAMAGE THE DM3 BY HOOKING IT UP WRONG ? - The DM3 has circuitry to protect itself from incorrect
hookup. If hooked up wrong, the unit will not work until it is hooked up correctly.
3. WHAT ARE SOME OF THE THINGS I MIGHT WANT TO MEASURE WITH THE DM3 ? - The basic things to
measure would be battery voltage and array current. This information is the minimum that you will need to know to
determine how your system is operating. You may also wish to measure the current consumed by your inverter or
load(s), so you will know if you are taking out too much energy from the system.
4. WHAT DO I NEED TO DO IF I CHANGE MY SYSTEM VOLTAGE ? - The DM3 will work in any system rated from
12 to 48 volts nominal. If you change your system voltage, the only thing that you will have to do is to recalibrate the
alarms, if you wish (see page 10).
5. WHAT DOES THE OPTIONAL ALARM RELAY OR BEEPER MODULE DO ? - If you would like some type of
warning that something is wrong with your system (other than from the red lights on the front of the unit), one of
these modules will help. The RELAY MODULE can be used to power a warning light or audible alarm at a location
removed from the DM3. The BEEPER MODULE will provide a very loud warning in the vicinity of the DM3. Both
modules monitor high- and low- voltage alarms.
6. WHAT CAN I USE THE AUX. INPUT FOR ? - This input can be used to measure a second system voltage (for
instance, voltage at the solar panels or at a particular load), or it may be used with a third external shunt to measure
a third system current. It may also be used with an insolation monitor to measure the amount of sunlight striking the
solar panels.. See page 10 for AUX. INPUT programming instructions.
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