Kenco Engineering KMD Transmitter - Manual (Page 3)

Page 3
INSTALLATION
Unpack the switch carefully. Inspect all units for damage. Report any damage to carrier immediately. Check the
contents against the packing slip and purchase order.
Kenco’s Magnetostrictive Liquid Level Transmitters are manufactured to the highest quality standards. These instruments
use electronic components that can be damaged by static electricity. Make sure that you are properly grounded before
starting installation. Insure that all electrical connections are properly made, and that there are no “floating” connections.
Operational Check
Before installing the transmitter, a simple operational check should be performed, as follows:
General Test
1. Open the electronics housing cover and connect power (see section on Wiring).
2. Using a DC Volt Meter, measure the voltage at the Loop #1 connections. The voltage must be >10.5Vdc and
<36Vdc.
3. If Loop #2 is being used, perform Step #2 on Loop #2.
4. If the voltage levels are not in range (10.5 – 36Vdc), turn off the power.
5. Check for shorts/opens, power supply voltage (at supply), and excessive loop resistance (see resistance chart in
section on Wiring).
6. If the voltage is too high, place a resistor in series with the transmitter to “drop” the excess voltage. Contact
Kenco if you need assistance in calculating the correct resistance value.
Loop #1 Test:
1. Connect a DC mA Meter in Loop #1
2. Lay the transmitter onto a flat surface.
3. Move the liquid level float along the operational range (zero to span) of the sensor. The output current should
change as the float moves.
4. If the loop current is less than 4mA or greater than 20mA, this could indicate a problem with the transmitter.
Contact Kenco for assistance.
Loop #2 Test:
1. Connect a DC mA Meter in Loop #2
2. If Loop #2 is being used to measure Liquid Interface, perform the Loop #1 test (steps 2 -4) with the interface float.
3. If Loop #2 is being used to measure Temperature, perform the following:
a. Measure the loop current.
b. Calculate the Temperature with the following formula:
c. The transmitter’s sensing RTD (Resistance Temperature Detector) is located approximately 3” from the
bottom tip of the sensor (unless a different location is specified when ordered). Measure the temperature at
this location to see if it is an approximation of the calculated value. If the output current is below 4mA or
greater than 20mA there may be a problem with the sensing RTD. Contact Kenco for assistance.
Threaded Flange Mounting
In applications with smaller vessels and tanks, the transmitter can be mounted directly to the vessel, by direct threaded
connection or mounting flange by using a threaded NPT fitting (supplied on the sensor). This fitting can be adjustable
(swaged) or welded to the sensor (determined by model configuration). If the float will not fit through the process
connection, there must also be some means to mount the float from the inside of the vessel (see the Float Access Port on
the following drawing).
( ) [ ] ( )
mA mA mA
T I T T T
4 4 20
4 16 + − Ч ч − =
Where:
T = Temperature
T
20mA
= Temperature @ 20mA Setpoint (Factory Setting: 300°F)
T
4mA
= Temperature @ 4mA Setpoint (Factory Setting: -30°F)
I = Output Current (in mA)