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signal. Herved dæmpes ventilationsanlæggets
evt. tryksvingninger i udgangssignalet.
NULSTILLING
Når transduceren er monteret og strømmen
tilsluttet, kan transduceren evt. nulstilles. Det
bedste resultat opnås når transduceren har nået
normal driftstemperatur. Før nulstilling aktiveres,
bør det sikres, at tryk på "+" og "-" studse er
ens, f.eks. ved at stoppe ventilationsanlægget.
Viser displayet over 10Pa differenstryk, kan det
skyldes utilsigtet tryk i anlægget (træk eller
afklemte slanger). Det anbefales, at trykslange(r)
er fjernet fra "+" og "-" studse, når nulstilling
udføres. Nulstilling startes ved at aktivere den
indbyggede "zero-set" switch (se fig. 3), hvor -
ved den gule lysdiode blinker indtil nulstillingen
er afsluttet.
LYSDIODE INDIKERING
Grøn LED lyser ved korrekt tilsluttet forsynings -
spænding. Gul LED blinker i ca. 3 sekunder
imens nulstilling udføres.
Lysdiode
ON
Blink
Grøn
OK
Nulstilling
Gul
udføres
FIGURER
Fig. 1:
Målskitse
Fig. 2:
Placering af transducer ifht. bøjninger
og forgreninger
Fig. 3:
Tilslutningsdiagram
Fig. 4:
Indstilling tryk/flow
Fig. 5:
Valg af måleområde
Fig. 6:
Ændring af måleenheder
Fig. 7:
Valg af måleenhedsskilt
Fig. 8:
Valg af udgangssignal
Fig. 9:
Valg af dæmpning
Fig. 10: Disponible DIP
Fig. 11: Trykindstilling
Fig. 12: Flow-indstilling
Fig. 13: Flow-beregningseksempel
Fig. 14: Kvadratrods-indstilling
OJ Electronics A/S
Stenager 13B · DK-6400 Sønderborg
Tel +45 73 12 13 14 · Fax +45 73 12 13 13
oj@oj.dk · www.oj.dk
English
PTH is an electronic pressure transducer
designed primarily to measure total and
differential air pressures in ventilation systems.
When used together with a standard aperture,
the pressure transducer can also measure air
flow as a formula for converting differential
pressure to air flow is incorporated in the
transducer. The pressure transducer is used for
monitoring, control and regulation purposes via
a controller, PLC or monitoring system.
Typical applications include:
- The maintenance/control of constant
pressure at a given position within the
ventilation duct system.
- The maintenance/control of desired
underpressure within the ventilation duct
system.
- Differential pressure measurement across
ventilation filter for optimum filter
replacement.
- Volume flow determination via differential
pressure measurement across a standard
aperture.
PRODUCT PROGRAMME
Type
Product
PTH-3202-DF
Pressure transducer, 0-2500 Pa,
display, flow
4
All manuals and user guides at all-guides.com
PTH-3202-BF
FUNCTION
PTH is a pressure transmitter for comfort
ventilation systems. It provides an active current
or voltage signal proportional to the measured
air pressure. If the pressure transducer is set for
flow measurement, differential pressure (Δp) is
converted to volume flow (qv) using the
following formula: qv = k•√Δp. PTH consists of
a semiconductor pressure element with no air
throughput, thus protecting the unit against
dust in the ventilation system. The pressure
element is temperature compensated to provide
accurate pressure measurement throughout the
specified temperature range.
The required measurement range of the
pressure transducer is set using three push
buttons. The buttons are also used to set the k-
factor to be used for flow calculation. Pressure
or flow is selected by simply changing a DIP
switch setting and replacing Pa with m3/h or l/s
Off
on the front cover.
Ingen
By selecting flow range P, PTH pressure
forsyning
transducers can directly replace pressure
transducers with existing square root output
OK
and flow display in %.
The output signal can be changed from voltage
[V] to current [mA] by setting a jumper. A DIP
switch allows two different damping times to be
selected so that pressure fluctuations within the
ventilation system are attenuated in the
transducer output signal. If the actual pressure /
flow is outside the selected measurement
range, the display flashes.
CE MARKING
OJ Electronics A/S hereby declares that the
product is manufactured in accordance with
Council Directive 92/31/EEC on electromagnetic
compatibility (and subsequent amendments)
and Council Directive 73/23/EEC on electrical
equipment designed for use within certain
voltage limits.
Applied standards
EN 61000-6-2 and EN 61000-6-3
TECHNICAL DATA
Full-scale
pressure range
Measurement ranges,
pressure
Measurement ranges,
flow
Square root output
k-factor
Supply voltage
Power consumption
Output signal
(selectable)
Accuracy (> 350 Pa)
Accuracy (< 350 Pa)
Pressure transducer, 0-2500 Pa,
back-lit display, flow
0-2500 Pa
-50..+50Pa, 0..+100Pa,
0..+150Pa, 0..+300Pa,
0..+500Pa, 0..+1000Pa,
0..1600Pa, 0..2500Pa.
P, 100 m
3
/h, 300 m
3
/h,
500 m
3
/h, 1000 m
3
/h,
3000 m
3
/h, 5000 m
3
/h,
9999 m
3
/h,
30.00 m
3
/h x 1000,
50.00 m
3
/h x 1000,
99.99 m
3
/h x 1000.
m
3
/h can be replaced
by l/s.
In the flow range P,
differential pressure is
measured as % of
full-scale pressure
range using square root
calculation.
1 to 2000
24V AC ±15%, 50/60 Hz
13.5-28 V DC
2.5 VA (+5/+40°C),
4 VA (-20/+5°C),
0-10 V DC, 2-10 V, DC
4-20 mA, 0-20 mA
±3% (recorded value)
±10 Pa
Linearity (at -20/+40°C) <1% of transducer
full scale
Damping (selectable)
0.4 s or 10 s
Max. pressure
20 kPa
Ambient temperature
0/+50°C (display)
-20/+40°C
(constant operation)
-30/+50°C (transient)
-50/+70°C (storage)
Dimensions
75 x 36 x 91 mm
(see figure 1)
Cable dimensions
3 x max. 1.5 mm
Pressure connector
2 x Ø6.2 mm
Enclosure
IP54
Weight
110 g
INSTALLATION
PTH must be securely mounted on a level
surface using screws. PTH is insensitive to
mounting orientation. However, in order to
maintain the specified enclosure rating, tubes
should be attached to both tube connectors if
the connectors point upwards. The enclosure is
equipped with screw holes, see fig. 1.
Pressure is connected by means of tubes. The
higher pressure must be connected to the "+"
connector and the lower pressure to the "-"
connector. If the tubes are unintentionally
exchanged, or the pressure is outside the
measurement range, the display flashes. The
pressure tubes must be as short as possible
and must be secured in position to prevent
vibration. To obtain the best possible results,
pressure must be measured where there is least
risk of turbulent air flow, i.e. in the centre of the
ventilation duct and at a suitable distance from
bends and branches. See fig. 2.
The enclosure is opened without the use of
tools by pressing the snap lock at the side of
the connectors. The transducer cable may be
up to 50 m in length and must be connected as
shown in fig. 3.
The transducer cable must be kept separate
from mains-carrying cables as voltage signals
from these may affect transducer function.
SETTINGS
Select pressure or flow by setting the DIP
switch (see figs 3 and 4). To display the
measurement range, press the "L" , "M" or
"OK" button on the rear cover once (see fig. 5).
If the buttons are not pressed again within 60
seconds, the display will revert to showing the
actual measured value. Press "L" or "M"
repeatedly to change the measurement range
up/down. The measurement range will flash on
the display until the setting has been saved by
pressing the "OK" button.
Pressure measurement (fig. 11): If the DIP
switch is set for pressure measurement, actual
pressure will be shown on the display.
Flow measurement (fig. 12): If the DIP switch is
set for flow measurement, pressing the "OK"
button allows the first digit of the k-factor to be
set. The value will flash and can be set using
the "L" and "M" buttons. When set correctly,
press "OK" and set the second, third and fourth
digits correspondingly. Then press "OK" to save
the k-factor and the display will automatically
begin showing the actual measured value. If
standard flow measurement is selected, no
pressure range need be set. An example of flow
calculation is shown in fig. 13.
Square root output (fig. 14): If flow range P is
selected, PTH functions as a pressure
transducer with square root output and flow is
displayed in per cent (Delta P [%]). Full-scale is
determined by the set pressure range (p-range)
and the value shown on the display is
calculated as Delta P [%] = 100x√(Δp/p-range).
When flow range P is selected, pressing "OK"
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