Fronius TransSteel 2500c, Operating Instructions Manual

Page: 52 / 120

52
In single-phase operation a safety cut-out function prevents a triggering of the fuse at high-
er welding power values. The safety cut-out function is active at fuse values of 15 A, 16 A
and 20 A and determines the possible welding time, without triggering of the fuse. If a cut-
out of the welding current results due to exceeding the pre-calculated welding time, the ser-
vice code „toF“ is displayed. In addition to the readout „toF“ from now on a countdown runs
for displaying the remaining waiting time, until the welding readiness is restored. Then the
message disappears an the power source is operational again.
At a fuse value of 30 A the temperature monitoring of the power source ensures the timely
shutdown of the welding current, yet before the fuse triggers. This results in the display of
the service codes „to1“ to „to7“. Detailed information concerning the servicecodes „to1“ to
„to7“ is located in chapter „Troubleshooting and maintenance, section „Displayed service
codes“. If there is no defect or soiling of the cooling components, here the power source is
also ready for welding again after an adequate welding break.
Explanation of
the term „duty cy-
cle“ in single-
phase operation For single-phase operation duty cycle values are given in the chapter „Technical data“, de-
pending on the existing fuse value and the welding current. The percentage rates of this
duty cycle values indeed relate as well to the 10-minute cycle, as explained in chapter
„Technical data“ for the general duty cycle, however the cooling phase of the fuse is rated
at only approximately 60 s. Thereafter, the power source is already operational again.
For reasons of technical standards the duty cycle in single-phase operation is only given
for the time until the cut-out within the first welding cycle takes place. If the reference to the
10 minute cycle would also persist with regard to the cooling phase, which is usually valid
for specifying the duty cycle, in practice longer welding phases than specified would be
possible. You see that the specification relates to cooling phases of only approximately 60
s, after which the power source is already operational again.
The example given in the following shows the standard compliant welding and break cy-
cles, at a welding current of 180 A and a duty cycle of 15 %.
Welding time in
single-phase op-
eration The following diagram shows the welding time, which is possible according to the technical
standards, depending on the given fuse value and the welding current.
t (min:s) 1:30 2:30 6:30 7:30 9 10 4 5
I (A)
180 A