First of all our diesel engine is equipped with an EGB-13P governor/actuator.
One of our test consists in simulating a failure of the electronic speed control module and check if the EGB-13P can take over and start up the engine.
Unfortunately, in this situation the hydraulic governor EGB is too slow to respond causing an overshoot at the startup. More than 10% of the rated speed. We've got in touch with Woodward, but the only advice they gave us so far is to adjust the needle valve.
In order to adjust it, we started the engine with a low speed setpoint then went up slowly to rated.
We noticed that when this valve is widely open the engine is hunting like crazy. So we closed a little the valve to adjust the hunting to an acceptable level of +/-1%. Actually, we are not sure whether or not this hunting is unsafe for the genset.
Despite this adjustment we still have the same problem of overspeed at startup. Our records show a little improvement in the overshoot which is now about 9%.
Also, there is this guy with us saying that the EGB is not made/designed to take over if the failure happens when the engine is not already running at rated speed. He says that we will always trip on overspeed if there is no load to "slow down" the engine at the moment of the failure.
Any help is welcome.
One of our test consists in simulating a failure of the electronic speed control module and check if the EGB-13P can take over and start up the engine.
Unfortunately, in this situation the hydraulic governor EGB is too slow to respond causing an overshoot at the startup. More than 10% of the rated speed. We've got in touch with Woodward, but the only advice they gave us so far is to adjust the needle valve.
In order to adjust it, we started the engine with a low speed setpoint then went up slowly to rated.
We noticed that when this valve is widely open the engine is hunting like crazy. So we closed a little the valve to adjust the hunting to an acceptable level of +/-1%. Actually, we are not sure whether or not this hunting is unsafe for the genset.
Despite this adjustment we still have the same problem of overspeed at startup. Our records show a little improvement in the overshoot which is now about 9%.
Also, there is this guy with us saying that the EGB is not made/designed to take over if the failure happens when the engine is not already running at rated speed. He says that we will always trip on overspeed if there is no load to "slow down" the engine at the moment of the failure.
Any help is welcome.