KMC TPE-1477-21 Duct Low Pressure Transmitter Instruction Manual
- June 5, 2024
- KMC
Table of Contents
Duct Low-Pressure Transmitter
Installation Instructions
TPE-1477-21
TPE-1477-22
INTRODUCTION
The Low-Pressure Transmitter can be used to measure positive, negative, or differential pressure in the ranges of 1″wc to 20″wc and 250 Pa to 5000 Pa. The highly accurate piezoresistive sensor is ideal for monitoring the pressure of non-corrosive, nonionic working fluids such as clean dry air or other inert gases. It features field selectable output signal types for the most flexible application. Typical HVAC applications include monitoring of filter differential pressure or cleanroom pressure. The output signal is factory calibrated and temperature compensated for the highest start-up accuracy and trouble-free operation.
BEFORE INSTALLATION
Read these installation instructions carefully before commissioning the Pressure Transmitter. Failure to follow these instructions may result in product damage. Do not use in an explosive or hazardous environment, with combustible or flammable gases, as safety or emergency stop devices, or in any other application where the failure of the product could result in personal injury. Use electrostatic discharge precautions during installation and do not exceed the device ratings.
MOUNTING
The transmitter mounts on a vertical surface using the two integrated mounting
holes. Ensure there is enough space around the unit to connect the pressure
tubing without kinking and to make the electrical connections, avoid locations
with severe vibrations or excessive moisture. Drill a hole in the duct and
insert it so the probe point is facing into the air flow. The enclosure has a
standard opening for a 1/2” conduit and may be installed with either conduit
and a conduit coupler or a cable gland type fitting. See Figure 1. The two
mounting holes will facilitate a #10 size screw (not supplied). See Figure 1.
The enclosure has a hinged cover with a latch. Open the cover by pulling slightly on the latch on the right side of the enclosure and at the same time pulling on the cover, as illustrated in Figure 2.
A 1/2″ NPT threaded connection hole is provided on the bottom side of the enclosure. Screw the EMT connector or cable gland connector in until tight. See Figure 3. It is recommended that weatherproof conduit or cable gland fittings be used. The F-style enclosure includes a 1/2″ NPT to M16 thread adapter and cable gland fitting. See Figure 3.
Make wiring connections as per the “Wiring” illustrations on page 2.
Two security screws are provided which can be installed to help secure the
cover once settings and wiring connections are complete. See Figure 4.
WIRING
The transmitter has standard screw block connectors and easy wire access to
facilitate wiring. It is recommended that shielded twisted pair wiring at
least 22 AWG be used for all connections and that the device wires not be run
in the same conduit with wiring used to supply inductive loads such as motors.
Disconnect the power supply before making any connections to prevent
electrical shock or equipment damage. Make all connections in accordance with
national and local electrical codes.
The device power (24 Vac/dc) is connected to the terminal marked PWR. This
terminal is used for the positive dc voltage or the hot side of the ac
voltage. The device is reverse voltage protected and as such will not operate
if connected backward.
For voltage output signal types (3-wire) or for AC power supply operation
(3-wire), the common of the power supply is connected to the terminal marked
COM. Note that this device has a half-wave type power supply which means the
power supply common is the same as the output signal common. Therefore,
several devices may be connected to one power supply and the output signals
all share the same signal common. Use caution when grounding the secondary of
an ac transformer or when wiring multiple devices to ensure that the circuit
ground point is the same on all devices and the controller. This terminal is
not used for loop-powered 4-20 mA output type (2-wire).
The analog output signal is available on the OUT terminal. This signal is
switch selectable for either a voltage output or a standard loop-powered 4-20
mA output signal type. The analog output signal is typically connected
directly to the Building Automation System (B.A.S.) and used as a control
parameter or for logging purposes.
For voltage type output signal the device has a minimum load that it is able
to drive, similarly for current type output signal the device has a maximum
load that it is able to drive with a particular power supply voltage. Observe
and follow these ratings in the Specification section or inaccurate reading
may result.
CONFIGURATION
The transmitter is configured with a jumper and a switch located on the
circuit board as shown on the PCB drawing in Figure 5. These are used to
select the output signal type and the bipolar range/unipolar range (± or
0-MAX).
The unit is factory condfigured to operate in the 4-20 mA output mode. To
change to 0-10 Vdc output move the switch to the VOLT position as shown in
Figure 6.
The unit is factory set to unipolar. To change to bipolar move the jumper to
the +/- position as shown in Figure 7.
For example, if the model is for 2″wc and the jumper labeled (±) is also
selected, then the pressure range will be -2 to +2″wc. This means that each
model has two pressure ranges, a bipolar range (±), and a unipolar range,
0-MAX.
PNEUMATIC CONNECTIONS
The one pressure port on the side of the enclosure is labeled Low. The static
probe is the High port. This output signal reads a positive value when the
port pressure is higher on the High port than on the Low port. Use 0.170″I.D.
flexible tubing for the pressure connections. Arrange the tubing to minimize
the stress on the connections and ensure there are no kinks in the tubing.
Ensure the tubing to be used is clean and do not allow material to fall into
the pressure ports as contamination could damage the sensor. When removing
tubing use care to avoid breaking the ports. In some cases, it is better to
cut the tubing off rather than pulling it off but be careful not to cut the
fitting or an air leak may occur.
POWER UP INSTRUCTION
Before turning on the power, verify all wiring to ensure that it complies with
one of the included wiring diagrams and verify that the output signal type is
correctly selected with the jumpers. Also, review the specifications to ensure
the power supply is correct and that the pressure is within the correct range.
At this time, also inspect the internal pressure tubing that connects the
sensor to the external ports to ensure that the tubing did not get kinked
during shipping or installation.
Proper operation can be verified by measuring the output signal. For voltage
output configuration, measure the voltage between the OUT and COM terminals.
The voltmeter should read between 0-10 Vdc. For the current output
configuration, insert an mA meter in series with the OUT terminal. The mA
meter should read between 4 and 20 mA.
OPERATION
If the unit is set to a unipolar range such as 0-2” wc, then the pressure applied to the High port must be higher than the pressure applied to the Low port. In this case, if the Low port is left open to ambient pressure and the High port is used to measure a positive pressure, then the output pressure can be calculated as follows:
4-20 mA: Pressure = [(Output current – 4 mA) / 16 mA] x Range
0-10 Vdc: Pressure = (Output voltage / 10 V) x Range
In the case of 0-2” wc, 4 mA or 0 V = 0” wc and 20 mA or 10 V = 2” wc. Since
the transmitter is linear, 1” wc would be 12 mA or 5 V. If the positive
pressure connection is reversed then the transmitter will always output 4 mA
or 0 V.
If the unit is set to a bipolar range such as ± 1” wc, then the pressure
applied to the High port should be higher than the pressure applied to the Low
port for a positive output response. In this case, differential pressure can
be measured using both ports. If the High port has a positive pressure with
respect to the Low port, then the output indicates a positive pressure.
Negative pressure is indicated if the High pressure is less than the Low
pressure. For bipolar ranges, the output pressure can be calculated as
follows:
4-20 mA: Pressure = [(Output current – 4 mA) / 16 mA] x 2 x Range – Offset
0-10 Vdc: Pressure = (Output voltage / 10 V) x 2 x Range – Offset
CALIBRATION
All pressure ranges are factory calibrated and no calibration is necessary.
The user should perform a ZERO adjustment at the time of installation. Make
sure the unit is warmed up for at least 10 minutes (1 hour is best) before
making a zero adjustment. With both ports open to the ambient pressure, press
and hold the ZERO button for at least 3 seconds. Release the button after at
least 3 seconds and the device will calculate and store the new zero point.
Generally, it is not recommended that the span calibration be performed in the
field. Contact the factory for information on this type of calibration.
SPECIFICATIONS
Pressure Ranges ………………………..±1″, ±2″, ±5″, ±10″, ±20″ WC,±250 Pa, ±500 Pa,
±1250 Pa, ±2500 Pa, ±5000 Pa
Accuracy …………………………………….±1% F.S. @ 22°C (72°F) including hysteresis, non-
linearity, and repeatability
Measurement Type …………………..Static, Velocity, & Total Pressure
Response Time ………………………….250 ms
Stability ………………………………………<±1% F.S.O. per year
Thermal Eects ………………………….<±3% over-compensated range
Compensated Range………………..0° to 50°C (32° to 122°F)
Proof Pressure ……………………………40″ W.C.
Burst Pressure ……………………………120″ W.C.
Operating Conditions ………………0° to 50°C (32° to 122°F), 10 to 90% RH, non-
condensing
Power Supply …………………………….20-28 Vac/dc (non-isolated half-wave rectified)
Supply Current ………………………….<4 mA for voltage output, 20 mA max for current
output
Input Voltage Effect ………………….Negligible over specified operating range
Protection Circuitry ………………….. Reverse voltage protected and output limited
Output Signal …………………………….4-20 mA (2-wire), 0-10 Vdc (3-wire), field
selectable
Output Drive Capabilities ………..Current: 400 ohms max @ 24 Vdc;
Voltage: 10K ohms min
Zero Adjustments ……………………..Push-button auto-zero
Wiring Connections ………………….Screw terminal block (14 to 22 AWG)
Pressure Connection ………………..Barbed ports for 5 mm (0.170″ ID) flexible tubing
Conduit Connection …………………1/2″ NPT conduit or cable gland
Enclosure …………………………………… Polycarbonate UL94-V0, IP65 (NEMA 4X) F style
includes thread adapter (1/2″ NPT to M16) and cable gland fitting
Approvals …………………………………..CE, RoHS
Country of Origin ………………………Canada
DIMENSIONS
PRINTED IN CANADA
IN-BL-ELPXXXXS-04; 01/21