JUMO 709040 TYA-110 thyristor power unit Operating Manual - Manual (Page 36)

5 Commissioning
36 Power units 02.06
5.3.1 Alteration of the current limit Imax, as a function of the voltage on
Terminal 9
With an internal limit of, for example, I
max
= 0.8 x I
Thy
, the external range of
variation is only 0 to 8V.
5.4 Setting the phase angle for the first half-wave
In the mode “burst-firing with phase-angle controlled start” the thyristor power
unit retards the firing point for the first half-wave after the start in burst-firing
mode.
The factory setting is an angle
α = 90°(electrical). This value can be altered
over the range
α = 0 — 90°by the trimmer (10) “angle set”.
The factory setting will be satisfactory in most cases.
Counter-clockwise (left) = advance the firing angle
α
Clockwise (right) = retard the firing angle
α
H
If it is nevertheless necessary to make an adjustment, then the
minimum switch-on current at the start of the burst is the criterion
for setting the angle
α.