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TM
INSTALLATION GUIDE
H720
OPERATION
The H720 is a current-sensitive transducer that monitors current (amperage) in
the conductor passing through it. The H720 has a 4-20 mA analog output that
corresponds to 0-20 A to 0-200 A flowing through the conductor (adjustable Span
setting). The status output is suitable for connection to building controllers or
other appropriate data acquisition equipment operating at up to 30 volts. The H720
requires a 12-30 VDC power supply to generate its output.
TROUBLESHOOTING
Problem
Solution
No Reading at Controller
• Check Zero and Span settings.
• Check for control voltage at sensor (< 30 V)
• Check for amperage in monitored conductor (> 1 A)
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
> 200 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.
ZERO AND SPAN SETTING
< 1 A (Sensor Min.)
SENSED AMPS
4mA
20mA
0A
20 to 200A*
*Adjusted with Span Setting
SENSOR OUTPUT
WIRING OPTIONS
Option 1:
COM
COM
+
OUT
+
PWR
4-20 mA
IN
PWR OUT
(12-30 VDC)
Span Zero
Automation
Panel
H720
Option 2:
COM
COM 4-20 mA
IN
COM
+
OUT
+
PWR
+
Span Zero
External
Power
Supply
Automation
Panel
H720
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.
Program controller to account
for the extra turns, e.g., if four
turns pass through the sensor
(as shown), then divide the
normal controller reading by 4.
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GlobalTestSupply
.com
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