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MM1820
POTENTIOMETER POSITION INPUT
DUAL LIMIT ALARM

FEATURES
bulletProvides Relay Contact Closures at a Present Potentiometer Position Input
bulletPotentiometer Values from 100 ohms to 100 kilohms
bulletFail safe, Latching and Adjustable Deadband Available
bulletRed and Green LED Alarm Status Indicators
bulletUnlimited* Choice of Input Ranges
bulletChoice of Power Options
bullet10 + 5 Year Warranty


DESCRIPTION

The MM1820 monitors the slide position of a potentiometer and provides two sets of spdt, 5 A alarm relays with two independently adjustable setpoints.  Each setpoint has a set of red/green LEDs to indicate alarm status. When the signal exceeds a particular setpoint, the relay becomes energized. To provide a fail safe operation (loss of power resulting in alarm state),select Option RR.  The module can be supplied as a HI/HI, HI/LO, or LO/LO alarm (HI/LO supplied if not specified).

Standard deadband on both alarms is fixed at 0.5% of span. (Option A provides adjustable deadband of 0.5% to 100% of span.) Option D, latching alarms has no deadband control. Once the limit has been reached, the alarm latches and power to the module must be momentarily interrupted to reset the alarm.

The module includes filtering and conditioning to reduce susceptibility to transients and noisy operations. It also utilizes a stable 1 V power supply to excite the potentiometer. Any value potentiometer from 100 ohms to 100 kilohms can be used.

TYPICAL APPLICATIONS

Tank level, valve or actuator position control, monitoring or warning.


MOUNTING

The module is designed to plug into a standard 11-pin relay socket.  Part number MP011 is a molded plastic socket suitable for mounting on a flat surface or 2 3/4 inch wide PVC snap track (TRK48). Use CLP-1 hold down clip if needed.  A Killark HK Series explosion-proof housing with dome and 11-pin socket is available (HKB-HK2D-11).  A DIN rail mounted socket (P/N DMP011) is available for 35mm symmetrical rail.

SPECIFICATIONS

INPUT POTENTIOMETER RESISTANCE
 any value from 100 ohms to 100 kilohms

INPUT SPAN ADJUSTMENT
70% to 100% of pot rotation

INPUT OFFSET ADJUSTMENT
0 to 25% of pot rotation

INPUT IMPEDANCE
>10 megohms

EXCITATION
1 V, 10 mA max load

SETPOINT
Each alarm
  0 to 100% of span

DEADBAND
Standard
  Fixed 0.5% of span

(Option A)
  0.5% to 100% of span\

RESPONSE TIME
20 ms typical

ACCURACY
±0.1% of span or 0.02 ohms,
  whichever is greater

COMMON MODE REJECTION
120 dB, DC to 60 Hz

RELAY CONTACTS
2 (spdt)
Resistive Load:
  5 A max, 150 W max
  220 VAC max, 30 VDC max

Inductive Load
  1/8 HP max at 120/240 VAC

TRANSISTOR OUTPUT (Option V)
Relay driver
  (12 V coil, > = 220 ohms)
or open-collector outputs
  sink 100 mA, 30 V supply max

LINEARITY (Option T)
±0.01% of span

OPERATING TEMPERATURE
 14°F to 140°F
-10°C to  60°C

TEMPERATURE STABILITY
±0.02% of span or 0.025%°C/°C
  whichever is greater

POWER
115 VAC 10%, 50/60 Hz
  (2.5 W max)
230 VAC 10%, 50/60 Hz
  (2.5 W max)

DC Power Option
  24 VDC (limits 21-32 VDC)
  Isolation, DC power supply to input common
    10 megohms

 

* Within specified range limits


CONNECTIONS
Power, AC L1 or DC +
Power, AC L2 or DC -
Potentiometer Excitation
Input +
Input -
Relay 1 NO
Relay 1 C
Relay 1 NC
Relay 2 NO
Relay 2 C
Relay 2 NC		 PINS
1
3
2
4
5
6
7
8
9
10
11