9
SEIKOM-Electronic GmbH & Co. KG
Fortunastr.20
D-42489 Wülfrath
Telefon: +49(0) 20 58/20 44
Fax: +49(0) 20 58 / 79 111
E-Mail:
Internet:
http://www.seikom-electronic.de
Mounting
DTM must be securely mounted on a level surface using screws. DTM is insensitive to mounting
orientation. However, in order to maintain the specified enclosure, tubes should be attached to both
tube connectors point upwards. The enclosure is equipped with screw holes.
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 measuring range, the green LED 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 turbulence, i.e. in the centre of the ventilation
duct and at a suitable distance from bends and branches.
Attend to the inlet way from min 6 x pipe inside diameter and the outflow zone from min 2 x pipe
inside diameter for optimum measuring results.
The enclosure is opened without the use of tools by pressing the snap lock at the side of the
connectors. The transmitter cable may be up to 50m in length and must be connected as shown. The
transmitter cable (shielded cable min. 0,5 mm²!) must be kept separate from mains-carrying cables as
voltage signals from these may affect transmitter function.
Settings
Pressure range is set by turning the dial, SW2 and can be set to 8 different intervals. The pressure
range can be set in intervals ranging from -50/+50 Pa to 0-5000 Pa (DTM04) or 0-2500 Pa (DTM05).
If the dial is set to values other than the specified positions (0-7), the pressure transmitter will interpret
the setting as position 7 corresponding to the highest pressure range. If the pressure transmitter is
inadvertently set to a pressure range lower than the pressure encountered in the connectors, the
green LED will light constantly.
The screw terminals of the pressure transmitter can provide a 0/2
– 10V output signal and/or a 0/4 –
20mA output signal.
The 0-
10V output signal is provided by terminal 2 with DIP1 of SW1 in position “Off”.
The 2-10V output signal is provided
by terminal 2 with DIP1 of SW1 in position “On”.
The 0-
20mA output signal is provided by terminal 4 with DIP1 of SW1 in position “Off”.
The 4-
20mA output signal is provided by terminal 4 with DIP1 of SW1 in position “On”.
Output signal damping time can be set to 0.4s or 10s using DIP2 of SW1. The transmitter measures
the pressure several times within the set time and the output signal consists of the average of these
measurements. This allows any pressure fluctuations within the ventilation system to be dampened in
the transmitter output signal.
Zeroing
The transmitter can be zeroed after it has been mounted and the power supply connected. Before
zeroing the transmitter, it is important to ensure that the pressure on the + and
– connectors is equal
(e.g. by stopping the ventilation system). If the yellow LED is constantly lit, the transmitter is measuring
a differential pressure of more than 50 Pa. This may be caused by unintended pressure within the
system (draughts or compressed tubing). It is recommended that tubes be removed from the + and
–
connectors during zeroing. Zeroing is activated by pressing the integrated zero-set switch, after which
the yellow LED will continue to flash until zeroing has been completed.
