Veris Industries H921 Install - Manual (Page 2)

VERIS INDUSTRIES
™
INSTALLATION GUIDE H921
Z201166-0E PAGE 2 ©2010 Veris Industries USA 800.354.8556 or 503.598.4564 / [email protected] 01101
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.
opEration
The H921 is a current transducer that senses current (amperage) in any of three
field-selectable ranges; zero-to-thirty, zero-to-sixty, or zero-to-one hundred twenty
amperes. These ranges represent the maximum current that can be applied to the
monitored conductor. The H921 transforms the monitored current into 4-20mA DC
output suitable for connection to building controllers or other appropriate data
acquisition equipment. The H921 requires 12-30VDC external power to generate its
output.
The H921 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 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.
3x
1A
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
4A
> 120A (Sensor max.)
For load currents greater than sensor maximum rating:
Use a 5 Amp (H68xx 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. : 100A ÷ 4 Turns = 25 Amps max. in monitored conductor
• Failure to follow these instructions can result in overheating
and permanent equipment damage.
Controller must be
programmed to account for the
extra turns. e.g., if three turns
pass through the sensor (as
shown) the normal controller
reading must be divided by 3.
< 3 A (Sensor Min.)
troublEshooting
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
• Assure that sensor core mating surfaces are clean and
that the core clamp is completely closed.
• Check polarity of sensor output connections
scaling
Set range switch. 1.
External Power
Sourcing Panel
(‑Common)
Sinking Panel
(+Common)
DDC
CONTROLLER
12-30VDC
Power Supply
AI
120
60
30
DDC
CONTROLLER
AI
COMM
4-20mA Out
120
60
30
DDC
CONTROLLER
AI
V(COM)
4-20mA
in Return
120
60
30
*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
120
60
30
Amperage Range
Selector Switch
120
60
30
Scale controller 2.
software to match
selected output.
SENSED AMPS
Selected Range*
4mA
0A
20mA
SENSOR OUTPUT
*Factory calibrated ranges selected
with the amperage range switch