Seikom Electronic RLSW4 Airflow Monitoring Device User Manual

: June 13, 2024
: SEIKOM ELECTRONIC

Table of Contents

RLSW4 Airflow Monitoring Device
Proper usage
Measuring principal
Technical data
Electrical connection
Optional plug connector
Setting the switch point
Commissioning RLSW4 (R)
References
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Seikom Electronic RLSW4 Airflow Monitoring Device - Featured
Image Airflow monitoring device
Manual for air flow monitor
RLSW4 / RLSW4R

RLSW4 Airflow Monitoring Device

Our products correspond to the
requirements of the European guidelines
WEEE 2012/19/EU – RoHS 2011/65/EU

The RLSW4 is a calorimetrical air flow monitor the is a cheap access to the world of watching air flows and is an alternative to known pressure cell, vane switches and fan belt monitors.
You can install the device with its flange or its PG7 simply and fast. With its built in potentiometer the switch point may be set infinitely variable. The transistor output is connected at flow and the yellow LED enlightens. Differences in the media temperature are compensated automatically.

Proper usage

The RLSW4 is to be used as an air flow monitoring device watching gaseous media within its technical data. Its application area is e.g. ventilation and air conditioning installations, filter watching, supply and exhaust gases.

Measuring principal

A temperature-sensitive resistor is heated according to the calorimetric measuring principle. The temperaturesensitive resistor is heated by a second resistor. A flow in the medium dissipates heat from the measuring resistor, causing the resistor temperature an impedance to change. This temperature change is evaluated. Since both the velocity and the temperature of the flowing medium affect the dissipated heat, a relationship must be created between flow and temperature. For this purpose, a second temperature-dependent measuring resistor is located next to the first one. The second measuring resistor (temperature compensation) is not heated and is only used for the temperature measurement.

flow >= switch point	signal output switches	yellow LED enlightens
flow < switch point	signal output does not switch	yellow LED does not

enlighten

Technical data

Type	RLSW4	RLSW4R	RLSW4R/140
Article No.	74825	74825/R	74825R/140

supply voltage	24V AC/DC	24V AC.DC	24V AC/DC
supply voltage tolerance	+/-5%	+1-5%	+/-5%
signal. supply voltage		–	–
power consumption	WA	1VA	WA
ambient temperature	-20..4- 0-C	-20..+60-C	-20..+60- C

signal output. flow		1 NOC	1 NOC

Attention!!

Connection and commissioning must be performed by properly authorized and qualified personnel!
Connection to mains supply (L, N) must be made by means of a protected isolating switch with the usual fuses. As a matter of principle, the General VDE Regulations must be complied with (VDE 0100, VDE 0113, VDE 0160).

Installation Instruction:

The sensor should be mounted in such a way that the air flow passes through the lateral opening. The marking is intended as an assembly aid.
Installation where there is low turbulence, if possible.
Do not install directly behind bends (distance approx 10x bend radius).
Install the probe in the middle of the duct where possible (distance at least 1/3 of the duct diameter from the wall).
Do not install directly behind the heating register (rapid changes in temperature may lead to the measured values being falsified.

Cleaning:
The airflow sensor contains a sensor element which is sensitivity to mechanical loading and which must not be touched with hard and pointed objects. Any cleaning that may be necessary is possible in water (also with addition of detergents). Let the unit drip off and dry renewed start-up.

Electrical connection

Seikom Electronic RLSW4 Airflow Monitoring Device - Electrical
connection

Optional plug connector

Pin	Colour	connection
1	brown	+Uv
2	white	GND
3	black	contact 13, NOC
4	blue	contact 14, GND

Dimension:

RLSW4R/140 immersion sensor tube differently about 130mm.

Seikom Electronic RLSW4 Airflow Monitoring Device -
connector

Setting the switch point

The relationship between air velocity and impedance change is non linear. In the lower flow velocity range, the impedance change is very large. In the upper flow velocity range, however, identical changes in flow velocity result in increasingly smaller impedance changes. When the switch point is set, it is important to note what change is to be monitored because different settings have certain disadvantages.
Note the following requirements:
Small flow change in high flow velocity range: The switch point must be selected very close to the normal flow reading since flow changes only lead to a very small change in the measured value. Since temperature compensation takes place with certain delay after the actual temperature change has occurred, this switch point setting is only suitable for the applications which have slow temperature changes in the medium.
Small flow change in low flow velocity range: The switch point can be selected at a greater interval from the normal flow reading because a change in flow velocity causes a very large change in the measured value. A temperature change has not effect on switching behaviour.
Large change in flow rate:
A Yes/NO statement is usually required here (e.g. fan running or fan stationary). You can therefore select a safety clearance which is so large that neither temperature changes nor turbulences can have an affect on switching behaviour.

Commissioning RLSW4 (R)

Commissioning the RLSW4 you need to follow these points:

install the device
connect the device regarding to the manual
set potentiometer “sensivity” (the unpainted trimmer to the right of the screw) to minimum sensivity
switch on supply voltage; The device is instantly operational.
switch on the working flow
turn potentiometer “sensivity” slowly to maximum until the yellow LED enlightens and the transistor output changes. To ensure proper operation you may turn the potentiometer slightly over the switch point.
to check for proper operation, please lower or switch off the flow. The yellow LED should darken and the transistor output disconnects.

The monitoring device is now set to watch the flow.

Frequently asked questions

Problem	Cause	Sollution
RLSW4 does not operate	wrong or none supply voltage	check the supply voltage
RLSW4 does not react on flow	sensor is installed wrongly	check the sensor’s

installation
RLSW4 shows unusual response| sensor is highly polluted| clean the sensor, refer to the regarding page in this manual

Mistakes and misprints are not to be excluded. All information „without guarantee“.
03/2022

SEIKOM-Electronic GmbH & Co. KG
Fortunastr.20D-42489 Wülfrath
Telefon: +49(0) 20 58/20 44
Fax: +49(0) 20 58 / 79 111
E-Mail:info@seikom-electronic.com
Internet:http://www.seikom-electronic.de