This is one of the more advanced models of the Woodward Inc. set of regulator and control modules, the SPM-A series. This unit is 9907-028, and is designed as a similar model to the less advanced 9905-001 unit in the series. The 9907-028 model is designed to check the phase angle and frequency of the utility bus and then an offline generator it is meant to be attached to and then paralleled.
The voltage inputs from the bus and generator are applied to separate the signal conditioner circuits, and they change the voltage input signal’s shape so they are able to be measured accurately. The phase angle for the 9907-028 is given a plus or minus range of 10 percent. The 9907-028 is one of the few Woodward SPM-A Synchronizers that are designed without any voltage matching capabilities. AX Control INC. is fully ready and willing to: buy, sell, repair, and resell this machine as well as many other of our products.