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Caution, Installation guide, Operation – Veris Industries H708 Install User Manual

Page 2: Troubleshooting, Calibration, H708

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Z201484-0E

PAGE 2

©2012 Veris Industries USA 800.354.8556 or +1.503.598.4564 / [email protected]

01121

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.

TM

INSTALLATION GUIDE

H708

OPERATION

The H708 is a current-sensitive switching device that monitors current (amperage) in
the conductor passing through it. A change in the conductor’s amperage that crosses
the adjustable switch threshold plus the hysteresis value causes 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 30 volts. The H708 requires no external power supply to generate
its output.

TROUBLESHOOTING

Problem

Solution

No Reading at Controller

• Check sensor calibration (see above)
• Check for control voltage at sensor (<30 V, <1.0 A)
• Check for amperage in monitored conductor (>1 A)

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.

4x

0.5A

DANGER: 5A CTs can present hazardous voltages.

Install CTs in accordance with manufacturer's instructions.

Terminate the CT secondary before applying current.

H68xx‑5A CT

240A

300A:

5A

> 135 A (Sensor max.)

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.

CALIBRATION

Before beginning calibration, establish normal load conditions.

OK!

A

OK!

Then choose either A or B below.

< 1 A (Sensor Min.)

A. To monitor under-current (belt loss, coupling shear, status)

A

OK!

!

B. To monitor over-current (mechanical problems, seized impeller)

A

OK!

!

OK!

STATUS

OK!

STATUS

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.

3.Turn the screw an
additional 1/4 turn
counter-clockwise for
operational margin.

Setpoint

Status

Open

STOP

Setpoint

Status

Closed

STOP

1/4

Setpoint

+

3. Turn the
setpoint screw
an additional 1/4
turn clockwise
for operational
margin.

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.

+

1/4

Setpoint

Setpoint

Status

Closed

STOP

Setpoint

Status

Open

STOP

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) to add range for a low current load on a high
current source.

For load currents less than sensor minimum rating:

Wrap the monitored conductor through the center window and around the sensor
body to produce multiple turns. This increases the current measured by the
transducer.