Omicron CMC 356, Reference Manual

Page: 95 / 114

Increasing the Output Power, Operating Modes
95
7 I
NCREASING THE
O
UTPUT
P
OWER
,
O
PERATING
M
ODES
The CMC 356 has a very large application diversity. The current outputs
offer enough output power to test all electromechanical relays.
In particular, the
CMC 356 offers a variety of types of single-phase operation
using its two galvanically separated three-phase current outputs with which
the output power from the units can be significantly increased.
In cases when the current or the output power - or even the number of
independent voltages or currents - is insufficient, it is possible to switch
individual amplifier groups of the
CMC 356 in parallel or to connect external
amplifiers (up to six independent additional channels) to the "LL out 1-6".
The option "LLO-2" extends the low level outputs by two more independent
generator triples “LL out 7-12”; refer to section 6.12, "Option LLO-2 (Low
Level Outputs)" on page 94.
The operating modes illustrated in the following sections can be set in the
Hardware Configuration of the OMICRON
Test Universe software.
7.1 Safety Instructions for High Current Output
Observe the following safety instructions when using the operating modes
and connection methods described in this chapter.
• For currents greater than 25 A, the test object (load) should be
exclusively connected to the 4 mm/0.16 " banana sockets and not to the
generator combination socket.
• Since a current of 32 A flowing through a test lead (2 m/6 ft. of length,
2.5 mm
2
) causes a loss of 15 ... 18 W, we recommend to use the
connection methods shown in this chapter.
• When connecting current outputs in parallel, it has to be ensured that the
test leads are only connected together immediately at the test object and
that the test leads have sufficient diameter.
• At maximum amplitude of the 128 A mode, the cable losses can amount
to 112 W for AC and 280 W for DC operation.
• At maximum amplitude of the 64 A mode, the cable losses can amount
to 28 W for AC and 140 W for DC operation.
• For applications drawing DC current: The test object (load) should be
exclusively non-inductive! Note that a load of, for example, 1 Henry can
store 50 J (Joule) at 10 A DC for a long period of time. Electrical shocks
with more than 350 mJ can be life-hazardous for the user.