Veris H720 Datasheet
H904 , H934 & H720
VERIS INDUSTRIES
VFD Switches and
Current Sensors
Variable Frequency Drive
Monitoring and Control
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
current monitoring
● Monitoring positive status on motors controlled by variable frequency drives
● Replacing pressure switches
● Measuring current and load trending
DETECTS BELT LOSS/COUPLING SHEAR!
DETECTS BELT LOSS/COUPLING SHEAR!
Fan/pump
Calibrated
Trip Point
O O
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.
Loss of Belt/Coupling Shear
On
Electrical
Failure
TM
H904
H934
H720
U.S. Patent No. 5,705,989
FEATURES (H720)
● Analog output
● Superior to Hall eec t 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 eects of frequency and amperage
changes associated with VFDs
● Nuisance Reduction feature...provides a secondar y 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 dierent congurations...added exibility
● 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 retrots...no need to remove conductor
● 5-year warranty
Maximize Reliability
Minimize Installed Cost
Year
SPECIFICATIONS
Sensor Power H904/H934: Induced from monitored conductor; H720: 12-30VDC
Insulation Class 60 0VAC RM S
Frequency Range H720: 10 to 80 Hz; H904/H934: 20 to 34 Hz for on/o status, 34 to 75 Hz for belt loss indic ation
Temperature Range -15° to 60°C (5° to 140°F)
Humidity Range 10-90% RH non-condensing
O Delay (H90 4/H934) 0 sec to 2 min.
Accurac y (H720) 0.5% (combined linearity, hysteresis, and repeatability)
Terminal Block Wire Size 24-14 AWG (0.2 to 2.1 mm2)
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.
800.354.8556
5
Warranty
+1 503.598.4564
www.veris.com
HQ00 01758.B 01131
800.354.8556
E150462
+1 503.598.4564
DIMENSIONAL DRAWINGS
H720
Removable/Adjustable Mounting Bracket
0.7"
(19 mm)
0.33"
(9 mm)
(80 mm)
3.13"
www.veris.com
**3.1”
(79 mm)
Removable Mounting Bracket
1.1”
(26 mm)
H904/934
0.8”
(21 mm)
1.0”
(25 mm)
Bracket can
be mounted
on three sides
for added
installation
exibility.
Self-gripping Iris
2.15"
(55 mm)
1.00"
(26 mm)
3.0"
(76 mm)
APPLICATION/WIRING DIAGRAM (H904)
Monitoring Fan /Pump Motors for Positive Proof of Flow
CONTACTOR
VFD
CONTROL
DI
2.8”
(70 mm)
Ø 0.3”
(8 mm)
2.5”
(64 mm)
3.0”
(76 mm)
* Terminal block may extend up to 1/8” over the height dimensions shown.
1.4”*
(36 mm)
EXAMPLE LINEAR OUTPUT (H720)
Scale software as shown
Requires 12-30VDC for sensor power
20mA
SENSOR OUTPUT
4mA
0A
SENSED AMPS
200A
Fan or Pump
Motor
NOTE: The H904 is not intended for use in staged pump or variable inlet vane applications.
ORDERING INFORMATION
MODEL AMPERAGE RANGE STATUS OUTPUT MIN. TRIP
POINT
H720
H904
H934 SP ST, N. O.
ACCESSORIES
DIN Rail Clip Set (AH01)
DIN Rail (AV01) and DIN Stop Clip (AV02)
HQ00 01758.B 01131
lower limit: 0A
Upper limit: 20 to 200A
3.5 - 135A, 20 - 75 Hz Max. N.O. 0.1A@30VAC/DC 3.5A or le ss
4-20mA n/a none Solid-core
AH01
RELAY
TYPE
none
HOUSING STATUS
Split-core
AV01
H934 RELAY CONTACT RATINGS
Resistive..................................5A@250VAC, 30VDC
TYPICAL COIL PERFORMANCE
Voltage AC DC
24V................................... 10mA 10mA
RELAY
LED
POWER LED
n n
n n n
AV02
UL
n
current monitoring
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