Woodward MSLC-2XT Master Synchronizer and Load Control available

Load Control

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The MSLC-2 has four load control modes available:

• Base load

• Import/export

• Process

• Utility unload

Load control begins with the breaker closure of the utility and another discrete input selecting the load

control mode wanted. If no load control mode is selected the MSLC-2 will be in the offline mode. The

system load immediately prior to breaker closure is used as the starting base load reference. On com

mand, the adjustable ramp allows smooth, time controlled loading into a set import/export level. A ramp

pause switch is provided to stop the ramp at any point.

The import/export control is an integrating control. It adjusts the percentage of rated load carried by the

individual generators, operating in isochronous load sharing, in order to maintain a set import/export or

base load level. The MSLC-2 will maintain a constant base load or import/export level even with chang

ing utility frequencies. The MSLC-2 provides switch inputs to allow raising or lowering the internal digi

tal base load or import/export reference. The control also provides a remote analog signal input for ref

erence setting, if desired. (Signal variety: 0 to 20 mA, 4 to 20 mA, 0 to 5 V, 1 to 5 V and 0 to 10 V)

The MSLC-2 is equipped with a utility unload switch, which provides an adjustable time controlled ramp

to lower the base load or import/export level. When the level is below an adjustable threshold, the

MSLC-2 issues a breaker open command to separate the utility from the local bus. The ramp pause

switch can be used to stop the utility unload at any point. The maximum load that the MSLC-2 can tell

the individual generators to carry is their rated loads. So, in the event that the plant load is greater than

the capacity of the operating generators, the utility unload will stop when 100% rated load is reached

on each of the operating generators. This prevents accidental overloading of the local generators.

The MSLC-2 also includes two adjustable load switches which can be used for external functions or

warnings when chosen system load levels are attained. The high and low limit switches may also be

activated when 100% or 0% load signal to the generators is reached.