Air Monitor VELTRON DPT 2500 User manual

Installation, Operation,
and Maintenance Manual
VELTRON DPT 2500
Ultra-Low Range Differential
Pressure & Flow Transmitter
Installation, Operation & Maintenance
Air Monitor Corporation provides complete
technical support between the hours of
7 a.m. and 5 p.m. PST, M-F
Contact our Service Department
Toll Free: 1-800-AIRFLOW
or fax us at 1-707-526-2825
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
TABLE OF CONTENTS
TABLE OF CONTENTS
INSTRUMENTWARRANTY ...................................................................................................................................... i
SECTION 1 – GENERALINFORMATION
1.1 DESCRIPTION .................................................................................................................................................. 1
SECTION 2 – PERFORMANCE SPECIFICATIONS
2.1 TRANSMITTER ............................................................................................................................................... 2
2.2 OUTPUTS ......................................................................................................................................................... 2
2.4 POWER ............................................................................................................................................................. 2
2.4 MATERIALS OF CONSTRUCTION ................................................................................................................. 2
SECTION 3 – INSTALLATION
3.1 RECEIVINGAND INSPECTION ........................................................................................................................ 3
3.2 LOCATION ....................................................................................................................................................... 3
3.3 MOUNTING ...................................................................................................................................................... 4
3.4 PROCESS CONNECTIONS ............................................................................................................................... 5
3.5 POWER/SIGNAL CONNECTIONS ................................................................................................................... 6
SECTION 4 – OPERATION
4.8 LOW PASS FILTER ........................................................................................................................................... 7
SECTION 5 – CALIBRATION
5.1 REQUIRED EQUIPMENT ................................................................................................................................. 8
5.2 PREPARATION ................................................................................................................................................. 8
5.3 TRANSMITTER INPUT CALIBRATION .................................................................................................... 9-10
SECTION 6 – MAINTENANCE ............................................................................................................................... 11
SECTION 7 – CUSTOMER SERVICE ..................................................................................................................... 12
APPENDIXA– FACTORY SET-UPINFORMATION SHEET ................................................................................. 13

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
i
INSTRUMENT WARRANTY
NOTICE OF PROPRIETARY RIGHTS
This document contains confidential technical data, including trade
secrets and proprietary information which are the sole property of
Air Monitor Corporation. The use of said data is solely limited to
use as specified herein. Any other use is strictly prohibited without
the prior written consent of Air Monitor Corporation.
INSTRUMENT WARRANTY
Air Monitor Corporation (hereinafter referred to as “Seller”)
warrants that at the time of shipment, products sold pursuant
to this contract will be free from defects in materials and
workmanship, and will conform to the specifications furnished
or approved in writing by Seller. No warranty is given that
delivered products will conform to catalog sheets, data sheets,
and the like, which are subject to change without notice.
Seller will repair or replace, at its option, any products listed
under this warranty which is returned freight prepaid to Seller
within the earlier of three (3) years after start-up or thirty-
nine (39) months after shipment that, upon test and
examination, proves defective within the terms of this warranty.
The warranty period for any item repaired or replaced shall
be for the time remaining on the warranty period of the original
components. Purchaser shall notify Seller in writing of such
defect within sixty (60) days of discovery of the defect.
This warranty does not extend to any product sold by Seller
which has been the subject of misuse, neglect, accident,
damage or malfunction caused by interconnection with
equipment manufactured by others, improper installation or
storage, or used in violation of instructions furnished by Seller,
nor does it extend to any product which has been repaired or
altered by persons not expressly approved by Seller. Nor does
Seller warrant equipment against normal deterioration due to
environment; nor items such as lamps, glass, and similar items
subject to wear or burnout through usage. Adjustments for
items or equipment not manufactured by Seller shall be made
to the extent of any warranty of the manufacturer or supplier
thereof.
Seller shall not be liable for any special or consequential
damages or for loss of damage, directly or indirectly arising
from the use of the products. Seller's warranty shall be limited
to replacement of defective equipment and shall not include
field removal and installation expenses.
The warranty set forth above is in lieu of all other warranties
either express or implied and constitutes the full extent of Air
Monitor Corporation’s liability to the customer, or any other
party for breach of warranty.
THERE ARE NO EXPRESS WARRANTIES EXCEPT AS
SET FORTH HEREIN AND THERE ARE NO IMPLIED
WARRANTIES OF MERCHANTABILITY OF FITNESS
FOR ANY PARTICULAR PURPOSE, WHICH ARE
PARTICULARLY DISCLAIMED.

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
1
SECTION 1 – GENERAL INFORMATION
1 – GENERAL INFORMATION
1.1 – DESCRIPTION
The VELTRON DPT 2500 is an electronic differential pressure transmitter designed to receive low magnitude pressure signals of
space or duct pressurization and reference pressures from static pressure sensors, or signals of total and static pressure from an
airflow measuring station, and convert the sensed differential pressure into a 4 to 20mADC output signal proportional and linear
to static or velocity pressure. An optional integral LCD digital display provides local indication of the measured process in
appropriate engineering units (in w.c., CFM, FPM, %, etc.). The VELTRON DPT 2500 is available in a NEMA1 brushed aluminum
enclosure with external wiring connections (Standard version) or a NEMA 12 painted steel enclosure with internal wiring connections
(Industrial version). All VELTRON DPT 2500’s contain an integral 3-way zeroing valve to aid in calibration.

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
2
SECTION 2 – PERFORMANCE SPECIFICATIONS
2 – PERFORMANCE SPECIFICATIONS
2.2 – OUTPUTS
Output Signal.
4.0 to 20.0 mADC (2 wire). Proportional and linear to
differential pressure or velocity
2.3 – POWER
Power Supply.
14 to 40 VDC unregulated. Power input is reverse polarity
protected.
Power Consumption.
0.5VA@ 24VDC
2.4 – MATERIALS OF CONSTRUCTION
Standard Version.
NEMA 1 aluminum enclosure with external power/signal
connections.
Industrial Version.
NEMA12, drawn 16 gauge steel enclosure with hinged cover,
quick-release latch and bulkhead signal and conduit
connections.
2.1 – TRANSMITTER
Pressure Spans Velocity Spans
0 to 0.10” w.c. 0 to 1266 fpm
0 to 0.25” w.c. 0 to 2003 fpm
0 to 0.50” w.c. 0 to 2832 fpm
0 to 1.00” w.c. 0 to 4005 fpm
0 to 2.00” w.c. 0 to 5664 fpm
0 to 5.00” w.c. N/A
0 to 10.00” w.c. N/A
Spans are Factory set.
Calibrated (Reference) Accuracy.
±0.50% of Natural Full Span, including non-linearity,
hysteresis, and non-repeatability.
Stability.
±0.5% of Natural Full Span for six months.
Temperature Effects.
Zero & Span – 0.015% of Natural Full Span/ºF
Mounting Position Effect.
Zero shift only; corrected through manual zeroing.
Integral Zeroing Means.
3-way, zeroing valve with manual switch.
Overpressure and Static Pressure Limit.
25 psig.
Temperature Limits.
–20 to 180ºF Storage; +32 to 140ºF Operating.

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
3
3– INSTALLATION
SECTION 3 – INSTALLATION
3.1 – RECEIVING AND INSPECTION
• Carefully remove the VELTRON DPT 2500 from the shipping container taking ESD (electrostatic discharge) precautions.
• Inspect unit for any damage. If damaged, contact freight company.
• Verify that the information recorded on the label on the bottom side of the unit is correct for your application.
If not, contact Air Monitor’s Service Department at 1-800-AIRFLOW for further guidance.
3.2 – LOCATION
• The standard version of the VELTRON DPT 2500 is a NEMA 1 enclosure suitable for most clean indoor locations. If additional
protection is required, mount unit in an enclosure with adequate NEMA rating.
• The industrial version of the VELTRON DPT 2500 is housed in a NEMA 12 enclosure (see NEMA ratings for degree of
protection).
• The ambient temperature of the selected mounting location must be between +40 to 120ºF. Consideration should be given to
units exposed to direct sunlight.
• The selected mounting location should be rigid and free of vibration.

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
4
SECTION 3 – INSTALLATION
3.3 – MOUNTING
• Tools Required: Electric drill; #25 (0.1495”) bit; screwdriver or nutdriver; and four #8-32 self-tapping machine screws.
• The VELTRON DPT 2500 can be mounted in any position provided it is secured using all four mounting holes.
• Reasonable consideration should be given to clearances for pressure and electrical connections.
• Once a suitable location is found, use the unit as a template to mark the centers of the four mounting holes.
• Drill four pilot holes at the marked locations. With the unit in position, install the four #8-32 screws.

VELTRON DPT 2500
Air Monitor Corporation
116-045-10.P65 (6/99)
VELTRON DPT 2500 - IO&M Manual
5
SECTION 3 – INSTALLATION
3.4 – PROCESS CONNECTIONS
The VELTRON DPT 2500 comes standard with brass ¼” tube compression fittings (or special fittings if ordered). To these fittings
connect the appropriate rigid or flexible tubing. Although any size tubing can be used, the response time of the VELTRON DPT 2500
to process change can increase if there is an increase in tubing size or an increase in tube length. The following table lists
recommended tube size versus length.
When connecting the VELTRON DPT 2500 to an airflow measuring device, connections must be completed as follows:
– High port on the DPT 2500 connects to Total Pressure from the airflow measuring device.
– Low port on the DPT 2500 connects to Static Pressure from the airflow measuring device.
When connecting the VELTRON DPT 2500 for positive room pressurization, connections must be completed as follows:
– High port on the DPT 2500 connects to sensor from monitored room.
– Low port on the DPT 2500 connects to reference sensor.
When connecting the VELTRON DPT 2500 for negative room pressurization, connections must be completed as follows:
– High port on the DPT 2500 connects to reference sensor.
– Low port on the DPT 2500 connects to sensor from monitored room.
CAUTION
It is extremely important that no pressure be present in signal tubing at the time of installation, and
the orientation of High and Low pressure signal lines is maintained between the source and the
VELTRON DPT 2500.
When making any tubing connections or changing fittings, use a 9/16” wrench to prevent the
1/8” FPT bulkhead fitting from turning.
Signal Line Length Recommended Tube Size
Up to 50' 1/4"
50' to 200' 3/8"
Over 200' 1/2"