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OPERATION
The H909 is a current-sensitive switching device that monitors current (amperage) in
the conductor passing through it. A change in amperage in the monitored conductor
that crosses the switch (setpoint) threshold plus the hysteresis value will cause
the resistance of the FET status output to change state, similar to the action of a
mechanical switch. In this model, the setpoint is adjustable through the action of a
twenty (20) turn potentiometer (see the CALIBRATION section). The status output is
suitable for connection to building controllers or other appropriate data acquisition
equipment operating at up to 120 volts. The H909 requires no external power supply
to generate its output.
The H909 housing offers unprecedented mounting flexibility. The mounting bracket
can be attached in three different places. Additionally, the bracket is compatible with
the Veris AH01 DIN Rail clip, allowing DIN mounting.
NOTES
For load currents greater than sensor maximum rating:
Use a 5 Amp (H68xx series) Current Transformer (CT) as shown. This technique can be
combined with wrapping (see below) when added safety is desired for a low current
load on a high current source.
4A
DANGER: 5A CTs can present hazardous voltages.
Install CTs in accordance with manufacturer's instructions.
Terminate the CT secondary before applying current.
CAUTION
RISK OF EQUIPMENT DAMAGE
• Derate the product's maximum current for the number of turns
through the sensing window using the following formula.
Rated Max. Amps ÷ Number of Turns = Max. monitored Amps
e.g. : 100A ÷ 4 Turns = 25 Amps max. in monitored conductor
• Failure to follow these instructions can result in overheating
and permanent equipment damage.
For load currents less than sensor minimum rating:
Wrap the monitored conductor through the center hole and around the sensor body
to produce multiple turns through the center window. This increases the current
measured by the transducer.
< 2.5 A (Sensor Min.)
Program controller to account
for the extra turns. e.g., if four
turns pass through the sensor
(as shown) divide the normal
controller reading by 4.
Z201495-0C
PAGE 2
Alta Labs, Enercept, Enspector, Hawkeye, Trustat, Veris, and the Veris 'V' logo are trademarks or registered trademarks of Veris Industries, L.L.C. in the USA and/or other countries.
H909
240A
> 135A (sensor max.)
5A
300A:
H68xx-5A CT
4x
1A
©2011 Veris Industries USA 800.354.8556 or +1.503.598.4564 / support@veris.com
INSTALLATION GUIDE
CALIBRATION
Before beginning calibration, establish normal load conditions.
OK!
A
Then choose either A or B below.
A. To monitor under-current (belt loss, coupling shear, status)
!
OK!
A
1. Turn setpoint screw
clockwise until Status OPEN
LED turns ON.
2. Slowly turn the screw counter-clockwise until the Status CLOSED LED just
turns ON.
Status
Setpoint
Closed
STOP
B. To monitor over-current (mechanical problems, seized impeller)
!
OK!
A
1.Turn setpoint screw
counter-clockwise until Status
CLOSED LED turns ON.
2. Slowly turn the setpoint screw clockwise until the Status OPEN LED just turns ON.
Status
Open
Setpoint
STOP
TROUBLESHOOTING
Problem
No Reading at Controller
• Check sensor calibration (see above)
• Check for control voltage at sensor (<120V)
• Check for amperage in monitored conductor (> 2.5A)
• Assure that sensor core mating surfaces are clean and
that the core clamp is completely closed
Setpoint screw has no stops
The setpoint screw has a slip-clutch at both ends of its
travel to avoid damage. Twenty turns CCW will reset
the sensor to be most sensitive. Repeat calibration
above.
Both LEDs are lit
Setpoint screw is too far clockwise. See solution above.
STATUS
OK!
Status
Setpoint
Open
STOP
3.Turn the screw an
Setpoint
+
additional 1/4 turn
counter-clockwise for
1/4
operational margin.
STATUS
OK!
Status
Setpoint
Closed
STOP
+
3. Turn the setpoint
Setpoint
screw an additional
1/4 turn clockwise for
1/4
operational margin.
Solution
08114
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