Installation
Version 1
RES-401
Page 15
You can find the exact configuration of the DIP switches in the ROPEX Application Report calculated for your par-
ticular application.
If the secondary current I
2
is less than 30A, the secondary high-current wire must be laid twice (or several times)
through the PEX-W3 or PEX-W4 current transformer (
ROPEX Application Report).
5.10
Replacing and "burning in" the heatsealing band
5.10.1 "Burning in" the heatsealing band
The heatsealing band is a key component in the control loop, since it is both a heating element and a sensor. The
geometry of the heatsealing band is too complex to be discussed at length here. We shall therefore only refer to
a few of the most important physical and electrical properties:
The measuring principle applied for this system necessitates a heatsealing band alloy with a suitable temperature
coefficient TCR. Too low a TCR leads to oscillation or uncontrolled heating.
When heatsealing bands with a higher TCR are used, the controller must be calibrated for this.
The first time the heatsealing band is heated to approximately 200…250°C, the standard alloy undergoes a once-
only resistance change (burn-in effect). The cold resistance of the heatsealing band is reduced by approximately
2…3%. However, this at first glance slight resistance change results in a zero point error of 20…30°C. The zero
point must therefore be corrected after a few heating cycles, i.e. the AUTOCAL function must be repeated.
The burn-in effect described here does not occur if the heatsealing band has already been thermally pretreated
by the manufacturer.
An overheated or burned-out heatsealing band must no longer be used because the TCR has been
altered irreversibly.
One very important design feature is the copper or silver-plating of the heatsealing band ends. Cold ends allow
the temperature to be controlled accurately and increase the life of the teflon coating and the heatsealing band.
3
2
1
4 5
ON
OFF
1...10V
6...60V
20...120V
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
ON
30...100A
60...200A
120...400A
OFF
ON
ON
OFF
OFF
ON
DIP switch
DIP switch
1 2
U
2
I
2
3
4
5
3
2
1
4
5
4
3
O
N
O
F
F
U
(
V
)
2
1-
10
SW
IT
C
H
ON
Factory settings
2x
!
