Veris Industries H720 Datasheet User Manual
Vfd switches and current sensors, Variable frequency drive monitoring and control, Current monit oring
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current monit
oring
VERIS INDUSTRIES
800.354.8556
+1 503.598.4564
www.veris.com
DESCRIPTION
Hawkeye 904, 934, and 720 current monitoring devices provide unique solutions
for accurately monitoring status of motors controlled by variable frequency drives.
The microprocessor-based H904 and H934 store the sensed amperage values
for normal operation at various frequency ranges in non-volatile memory. This
information allows the device to distinguish between a reduced amp draw due to
normal changes in the frequency and an abnormal amp drop due to belt loss or other
mechanical failures. The relay on the H934 is isolated from the current switch, and all
relay connections are externally accessible on the device.
The H720 analog output corresponds to current in the monitored conductor from 10
to 80 Hz.
APPLICATIONS
●
Monitoring positive status on motors controlled by variable frequency drives
●
Replacing pressure switches
●
Measuring current and load trending
FEATURES (H720)
●
Analog output
●
Superior to Hall effect and metal core sensors...frequency tolerant 10-80 Hz
●
Accurate to 0.5% of full scale
●
Suitable for load side monitoring of VFDs
●
Adjustable zero and span for precise scaling
●
Adjustable mounting bracket for easy placement
FEATURES (H904 and H934)
●
Microprocessor-based...real labor saver...No need to calibrate to
detect belt loss on VFDs
●
Self-adjusting trip point...factory programmed to detect belt loss
undercurrent conditions
●
Provides accurate status for VFD loads...prevents costly long-term failures
●
Automatically compensates for the effects of frequency and amperage
changes associated with VFDs
●
Nuisance Reduction feature...provides a secondary setpoint option of
50% of the originally measured current
●
LED indicates normal and alarm conditions...rapid troubleshooting
●
Huge labor savings...no need to calibrate in live starter enclosures...
install and go
●
Available with a relay (H934)...status and control in one package,
saving time and space
●
Bracket can be installed in three different configurations...added flexibility
●
Monitors both frequency and amperage...distinguishes normal drops in
amperage due to frequency changes from abnormal drops due to
mechanical failure
●
Split-core design is ideal for retrofits...no need to remove conductor
●
5-year warranty
Variable Frequency Drive
Monitoring and Control
VFD Switches and
Current Sensors
SPECIFICATIONS
Sensor Power
H904/H934: Induced from monitored conductor; H720: 12-30VDC
Insulation Class
600VAC RMS
Frequency Range
H720: 10 to 80 Hz; H904/H934: 20 to 34 Hz for on/off status, 34 to 75 Hz for belt loss indication
Temperature Range
-15° to 60°C (5° to 140°F)
Humidity Range
10-90% RH non-condensing
Off Delay (H904/H934)
0 sec to 2 min.
Accuracy (H720)
0.5% (combined linearity, hysteresis, and repeatability)
Terminal Block Wire Size
24-14 AWG (0.2 to 2.1 mm
2
)
Terminal Block Torque
3.5 to 4.4 in-lbs (0.4 to 0.5 N-m)
Agency Approvals
UL 508 open device listing
Do not use the LED status indicators as evidence of applied voltage.
U.S. Patent No. 5,705,989
H904
H934
H720
Year
Warranty
5
H904 , H934 & H720
TM
DETECTS BELT LOSS/COUPLING SHEAR!
DETECTS BELT LOSS/COUPLING SHEAR!
Now you can easily detect when drive belts slip, break, or pump couplings shear.
In fact, a typical HVAC motor that loses its load has a reduction of current draw
of up to 50%. That’s why our sensors are the industry standard for status.
Calibrated
Trip Point
Off
Off
Fan/pump
On
Loss of Belt/Coupling Shear
Electrical
Failure
Maximize Reliability
Minimize Installed Cost
HQ0001758.B 01131