5
2.2 Electrical: Input/Output
Input Power
100 to 240 VAC, 50 or 60 Hz, 7 A maximum
Fuse: 6.3 A
Inputs
Copper/Nickel Sensor Signals (0, 1 or 2 depending on model code):
Copper
Walchem 190787 immersible OR 190785, 190893, 191596 flow through
sensors
Nickel
Walchem 190784 flow through sensor
Sensor Input Signals (0, 1 or 2 depending on model code):
Contacting Conductivity
0.01, 0.1, 1.0, or 10.0 cell constant OR
Electrodeless Conductivity
(not available on the combination sensor/analog input card) OR
Disinfection
OR
Amplified pH, ORP or ISE
Requires a preamplified signal. Walchem WEL or WDS series recommended.
±5VDC power available for external preamps.
Each sensor input card contains a temperature input
Temperature
100 or 1000 ohm RTD, 10K or 100K Thermistor
Analog (4-20 mA) Sensor Input (0, 1,
2 or 4 depending on model code):
2-wire loop powered or self-powered transmitters supported
3 or 4 –wire transmitters supported
Each dual sensor input board has two channels
Channel 1, 130 ohm input resistance
Channel 2, 280 ohm input resistance
The combination input board has one channel, 280 ohm input resistance
Available Power:
One independent isolated 24 VDC ± 15% supply per channel
1.5 W maximum for each channel
2W (83 mA at 24 VDC) total power consumption for all channels (four
total channels possible if two dual boards are installed; 2W is equivalent to
2 Little Dipper sensors)
Digital Input Signals (6):
State-Type Digital Inputs
Electrical: Optically isolated and providing an electrically isolated 9V
power with a nominal 2.3mA current when the digital input switch is
closed
Typical response time: < 2 seconds
Devices supported: Any isolated dry contact (i.e. relay, reed switch)
Types: Interlock
Low Speed Counter-Type Digital
Inputs
Electrical: Optically isolated and providing an electrically isolated 9VDC
power with a nominal 2.3mA current when the digital input switch is
closed 0-20 Hz, 25 msec minimum width
Devices supported: Any device with isolated open drain, open collector,
transistor or reed switch
Types: Contacting Flowmeter, Flow Verify
High Speed Counter-Type Digital
Inputs
Electrical: Optically isolated and providing an electrically isolated 9VDC
power with a nominal 2.3mA current when the digital input switch is
closed, 0-500 Hz, 1.00 msec minimum width, Minimum pulse rate to see
paddlewheel rate = 0.17 Hz
Devices supported: Any device with isolated open drain, open collector,
transistor or reed switch
Types: Paddlewheel Flowmeter, DI Counter
Note: Total available power on the Digital Input 9 VDC is 111 mA
