CSNZ-904 Series
Split-Core Adjustable Set
Point Digital Output Variable
Frequency Drive Current
Sensors
DESCRIPTION
The CSNZ-904 Series microprocessor-based current
sensors provide a unique solution for monitoring the
status of motors controlled by variable frequency drives
(VFD). The CSNZ-904 Series stores the sensed
amperage values for normal operation at various
frequency ranges in non-volatile memory. This
information allows the sensor to distinguish between a
reduced amperage draw due to normal changes in the
frequency and abnormal amperage drop due to belt loss,
coupling shear or other mechanical failures.
The self-adjusting trip set point is factory programmed to
detect belt loss in undercurrent conditions. The sensor
monitors both frequency and amperage, and
automatically compensates for change effects
associated with VFDs. There is no need to calibrate the
CSNZ-904 Series in live starter enclosures.
Status LEDs indicate normal and alarm conditions. The
split-core allows fast retrofit installation.
A DIN rail clip set (available separately) increases
mounting flexibility.
NOTE: The CSNZ-904 Series is not intended for use in
staged pump or variable inlet vane applications.
FEATURES
• Amperage range of 3.5 A to 135 A, 20 Hz to 75 Hz
• 0.1 A at 30 Vac/dc output rating
• Self-adjusting trip set point
• 100% solid state
• Microprocessor-based
• Normal and alarm status LEDs
• Self-gripping mounting teeth
• Split-core design
• cULus approved
POTENTIAL APPLICATIONS
• Monitoring positive status on motors controlled by
VFDs
• Replacement for pressure switches
CSNZ-904 Series
2 www.honeywell.com/sensing
SPECIFICATIONS
Characteristic Parameter
Amperage range 3.5 A to 135 A (at all frequency levels)
Sensor power induced
Status output rating N.O. 0.1 A @30 Vac/dc (non-polarity sensitive)
Output digital switch
Off state leakage 0 (open switch represents 1 + MOhm of resistance)
Insulation class 600 Vac rms (max. voltage when monitoring an uninsulated conductor)
Frequency range on/off status only: 20 Hz to 34 Hz
belt loss indication: 35 Hz to 75 Hz
Temperature range -15 ºC to 60 ºC [5 ºF to 140 ºF]
Humidity range 0% to 95% non-condensing
Off delay 0 s to 2 min
Trip setpoint self-calibrating/automatic setting
LED status* single pulse = normal
double pulse = alarm
Dimensions (L x W x H) 74 mm x 66 mm x 26 mm [2.90 in x 2.58 in x 1.04 in]
Sensor hole size (L x W) 28 mm x 23 mm [1.10 in x 0.90 in]
Approvals cULus UL 508
*Do not use the LED indicators for evidence of applied voltage.
MOUNTING DIMENSIONS (For reference only mm/[in].)
Split-Core Adjustable Set Point Digital Output Variable Frequency
Drive Current Sensors
Honeywell Sensing and Control 3
BELT LOSS/COUPLING SHEAR DETECTION
The CSNZ-904 Series detects when drive belts slip, break or pump couplings shear by sensing a drop in current. A
typical HVAC motor that loses its load has a current reduction draw of up to 50%.
APPLICATION/WIRING EXAMPLE
ORDER GUIDE
Catalog Listing Description
CSNZ-904 Split-Core Adjustable Set Point Digital Output Variable Frequency Drive Current Sensor
AH01 DIN Rail Clip Set
Automation and Control Solutions
Sensing and Control
Honeywell
1985 Douglas Drive North
Golden Valley, Minnesota 55422
www.honeywell.com/sensing
005858-1-EN IL50 GLO Printed in USA
November 2005
© 2005 Honeywell International Inc.
W
ARNING
PERSONAL INJURY
DO NOT USE these products as safety or emergency
stop devices or in any other application where failure
of the product could result in personal injury.
Failure to comply with these instructions could
result in death or serious injury.
WARRANTY/REMEDY
Honeywell warrants goods of its manufacture as being
free of defective materials and faulty workmanship.
Honeywell’s standard product warranty applies unless
agreed to otherwise by Honeywell in writing; please refer
to your order acknowledgement or consult your local
sales office for specific warranty details. If warranted
goods are returned to Honeywell during the period of
coverage, Honeywell will repair or replace, at its option,
without charge those items it finds defective. The
foregoing is buyer’s sole remedy and is in lieu of all
other warranties, expressed or implied, including
those of merchantability and fitness for a particular
purpose. In no event shall Honeywell be liable for
consequential, special, or indirect damages.
While we provide application assistance personally,
through our literature and the Honeywell web site, it is up
to the customer to determine the suitability of the product
in the application.
Specifications may change without notice. The
information we supply is believed to be accurate and
reliable as of this printing. However, we assume no
responsibility for its use.
W
ARNING
MISUSE OF DOCUMENTATION
• The information presented in this product sheet is
for reference only. Do not use this document as a
product installation guide.
• Complete installation, operation, and maintenance
information is provided in the instructions supplied
with each product.
Failure to comply with these instructions could
result in death or serious injury.
SALES AND SERVICE
Honeywell serves its customers through a worldwide
network of sales offices, representatives and distributors.
For application assistance, current specifications, pricing
or name of the nearest Authorized Distributor, contact
your local sales office or:
E-mail: info.sc@honeywell.com
Internet: www.honeywell.com/sensing
Phone and Fax:
Asia Pacific +65 6355-2828
+65 6445-3033 Fax
Europe +44 (0) 1698 481481
+44 (0) 1698 481676 Fax
Latin America +1-305-805-8188
+1-305-883-8257 Fax
USA/Canada +1-800-537-6945
+1-815-235-6847
+1-815-235-6545 Fax
