Veris Industries H721HC Install - Manual (Page 2)

6%2)3 INSTALLATION GUIDE H721HC
Z202940-0A PAGE 2 ©2008 Veris Industries USA 800.354.8556 or 503.598.4564 / [email protected] 09084
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.
240A
300A: 5A
opEration
The H721HC is a current transducer that senses current (amperage) in any of three
field-selectable ranges: 0-50, 0-100, or 0-200 amperes. These ranges represent
the maximum current that can be applied to the monitored conductor. The H721HC
transforms the monitored current into a 4-20mA output suitable for connection to
building controllers or other appropriate data acquisition equipment. The H721HC
requires 12-30VDC external power to generate its output.
notEs
SENSED AMPS
Selected Range*
4mA
0A
20mA
SENSOR OUTPUT
*Factory calibrated ranges selected
with the amperage range switch
troublEshooting
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 "window." This increases the current measured
by the transducer.
• Controller must be programmed to account for
the extra turns. e.g., if four turns pass through the
sensor (as shown) the normal controller reading
must be divided by 4.
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.
H681x-5A CT
> 200A (H721HC max.)
For load currents greater than sensor maximum rating:
Use a 5 Amp (H681x series) Current Transformer (CT) as shown.
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. : 30A ÷ 4 Turns = 7.5 Amps max. in monitored conductor
Failure to follow these instructions can result in overheating
and permanent equipment damage.
Problem Solution
No Reading at Controller •Confirm that you have 12-30VDC in series with the
sensor output terminals and the control panel analog
input.
• Confirm measured current is within the selected
range on the product.
• Check polarity of sensor output connections.
External Power
Sourcing Panel (-Common)
*A resistor can be added in parallel to convert the 4-20mA signal to a VDC signal (250 ohm=
1-5VDC); (500 ohm = 2-10VDC)
Wiring ExamplEs
DDC
CONTROLLER
PS Series
Power Supply
AI +
+V
–
-V NC
DDC
CONTROLLER
AI
COMM
4-20mA Out
+
–
DDC
CONTROLLER
AI
V(COM)
4-20mA
in Return
+
–
Sinking Panel (+Common)
Amperage Range
Selector Switch
200
100
50
200
100
50
calibration/scaling
Set the amperage range selector switch to a level appropriate for your load. The
H721HC is available with three choices, 0-50, 0-100, or 0-200 Amps.
10x
300A
5A
300A
Controller:
CT max / H721HC max
300 / 50 = 6x
20mA --> 300A
(slide switch set to 50 A)