DETAILED OPERATION - Section 4
MTS-1700 SERIES OPERATION AND REFERENCE MANUAL 4-11
CU A002 15A
MANTA TEST SYSTEMS
4.5.9
Testing SCR Output Type Relays
Relays with SCR outputs can be tested using the connection diagram shown below. Dynamic operation
mode should be used.
When [FAULT] is depressed, the fault quantities are applied to the relay, and the [AUX CONTACTS] close,
allowing current to flow in the SCR when the relay operates. When the relay operates, the appearance of
voltage across the load trips the stop trigger of the MTS-1710, causing it to go to the postfault state, and
open the [AUX CONTACTS] which breaks the SCR current.
FIGURE 4.9 TEST CONNECTIONS FOR SCR OUTPUT TYPE RELAYS
If the relay normally operates in less than two cycles, you’ll have to set the auxiliary contact arrangement
to type 52A (See Section 5.15.2). This will ensure the voltage is available to the SCR before the fault is
applied.
OP
Set DC voltage output
to DC relay coil rating
or use an external
DC source.
RELAY UNDER
TEST
DC relay coil or 500-1000 ohm,
15W resistor used as a load.
