Loads 49, 6 settings – JUMO 709040 TYA-110 thyristor power unit Operating Manual User Manual
Page 49
49
6 Settings
6.9.1 Free-running economy circuit (asynchronous switching) for resistive
loads
A free-running economy circuit has the advantage that the average loading of
the supply network is reduced. Both power units operate independently and
regulate the required 3-phase power quite precisely. Even a possible part-load
failure will not necessarily have an effect on the temperature stability of the
control loop.
A subsidiary P control loop is required for both power units.
If S12 and S13 are closed, it is not possible to change over to phase-angle control.
v Section 2.3 “Burst-firing operation for transformer loads and loads with a
high positive temperature coefficient TC (mixed operation)”
6.9.2 Master-slave economy circuit (synchronous switching) for resistive and
transformer loads
In the standard version, the master-slave economy circuit operates with a V
2
control. With extra code TO/TR it is also possible to use a P control and part-
load regulation. The control electronics of the master unit takes on the actual
power control function, and drives the slave unit in synchronization. This
makes it possible to drive transformer loads.
The combination of the fixed cycle time of the V
2
control and the delta load
configuration makes it possible to achieve good voltage regulation for the indi-
vidual load resistances, even in the event of a part-load failure.
v Section 4.7 “Master-slave economy circuit, with resistive/inductive loads”
Switch
S3
S4
S5
S6
S10
S11
S12
S13
S14
S17
S18
S20
S21
Economy circuit
(free-running)
■ resistive load
0
0
1
0
1
0
0
0
1
1
1
2
(master-slave)
■ resistive load
- master function
0
1
0
1
1
1
1
- slave function
0
1
0
0
2
2
1
■ transformer load
- master function
0
0
1
1
1
1
1
1
2
1
- slave function
0
0
1
1
1
0
2
2
2
1
H
The jumpers on pin header X503 of the slave unit must be turned
through 90° !
v Section 6.2 “Adjustment switches S1 — 21 and pin headers X503