Installation, Electrical connections, Power – Badger Meter K-Factor Scaler User Manual

Page 7: Turbine meter, Pulse output, Internal pullup resistor, Installation 7

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INSTALLATION

Refer to

Figure 2

for the I/O terminal connections The board connections include power input, turbine meter input, and the

pulse output to a totalizing device

1

2

3

4

5

6

Signal

Input

Output
Output
Vin
Vin

Programming

Port

Internal 3.6k Ω

Pullup

Resistor Jumper

Figure 2: Input/Output terminal connections

Enclosure Mounting (necessary for CSA certification)

If supplied without an enclosure you must mount the circuit board assembly within a certified Killark one inch NPT model Y-3

conduit elbow outlet box to maintain the CSA “Ordinary Locations” certification

Electrical Connections

The board connections include power input, turbine meter input, and the pulse output to a totalizing device

Power

The K Factor Scaler requires 8 5…30V DC to operate and is diode protected

Figure 2

shows the supply polarity

Turbine Meter

The turbine meter connections are non-polarized Blancett recommends shielded, twisted pair wire for this connection

Pulse Output

Either the internal or an external pullup resistor is required for the K Factor Scaler to provide an output pulse An onboard

jumper controls the pullup resistor selection With the jumper installed, the internal pullup resistor is connected Without the

jumper, an external pullup is required Refer to

Figure 2

for the I/O terminal connections

Internal Pullup Resistor

The internal pullup resistor allows for a simple installation, but be careful to ensure that the device being connected to

the pulse output can accept voltage levels as high as the supply feeding theK Factor Scaler Another important setup

consideration when using the internal pullup resistor is to make certain the output pulse from the K Factor Scaler can supply

enough current for the receiving device to read the pulse Calculation of the available current that the K Factor Scaler can

supply to the receiving device uses the following equation (see

Figure 3

)

Available Current =

(Input Voltage - 0.7V)

(3600Ω + 47Ω)

Using the above equation the maximum current available at an input voltage of 30V is 8 mA Verify that the receiving device

input current requirement is below this value for proper operation Otherwise, an external pullup resistor less than 3 6 kΩ

is required

User Manual

Page 7

November 2013

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