DSLC Digital Synchronizer and Load Control
Manual 02007
16
Woodward
Voltage Matching Relays
Optional voltage matching relays are connected to the raise and lower inputs on
the voltage regulator MOP (motorized potentiometer). Do not attempt to drive
MOP inputs directly with discrete outputs. Make the connections as shown in
Figure 1-3 as required to terminals 23 and 24 of the control.
Load Management Relays
The DSLC control provides three relay drivers for connection to customer-
supplied relays for load management. These drivers include an adjustable set
point load switch and high and low limit switches that are user-selectable as
adjustable load switches or as alarm indicators for reaching other high and low
limits. Make the connections as shown in Figure 1-3 as required to terminals 25,
26 and 27 of the control.
NOTE
If the load switch (terminal 25) is enabled as a reverse power trip, the load
switch is disabled.
Alarm Relay
Make the alarm relay connection as shown in Figure 1-3 to terminal 28 of the
control. Alarm conditions are selectable by the user.
Discrete Inputs
The discrete inputs are the switch input commands to the DSLC control. Discrete
inputs are optically isolated from the control and require 10 mA at 24 Vdc each to
activate. Discrete inputs may be powered by the same source as control power.
All contacts used in the discrete circuits should be the isolated dry contact type to
work properly with the low currents used in these circuits.
Connect the 24 Vdc supply common (
) to terminal 43. Route +24 Vdc through the
appropriate external contact to the discrete input.
Synchronizer Mode Switch
The synchronizer mode switch (single-pole, four-position) controls the operating
mode of the synchronizer. The switch must be wired to terminals 44, 45, and 46,
as shown in Figure 1-3. The four positions are Off, Check mode, Permissive
mode, and Run mode. When the switch is off, the synchronizer is out of
operation.
CB Aux Contact
Connect circuit breaker auxiliary (CB Aux) contacts that open and close when the
generator breaker opens and closes. Wire the breaker auxiliary contacts in
series between the +24 Vdc voltage source and terminal 47 of the DSLC control.
Wire an isochronous/droop switch in series with the circuit breaker auxiliary
contacts if both isochronous and droop operation are required (closed for
isochronous and open for droop; see Figure 1-3).