The differential function of the 469 is for differential protection of the motor windings. This protection can detect motor problems before motor failure. You must have six current transformers for this function (one on each side of each motor winding)
Interesting problem. I do not understand the reverse power trip unless you have multiple generators. Generators react poorly to leading power factor. This is interpreted by the generator controls as the generator being over excited, and lowers the excitation voltage until control of the...
The issue of three or pole is shrouded by myth, with most myths focusing on issues with ground fault. If the wrong scheme is chosen there will be issues. Choosing the right system is determined by whether or not the generator neutral is bonded to ground at the generator. See attached file for...
As a application engineer for a UPS manufacturer (not Mitsubishi), it appearts to me the issue is UPS sizing. There is nothing in the thread that indicated there is a problem with the Mitsubishi UPS. The UPS is a 100KVA box @ .8 PF - meaning the 100% full load is 80 KW. At roughly 105% load...
A couple of important notes on UPS - Standby generator applications.
1) Generator sizing must take UPS harmonics into considerations. Several factors determine final sizing including UPS harmonic filters, generator sub-transient reactance, and non UPS load on the generator.
Rectifier Power...
There are a number of reasons to use a Reduced Voltage Solid State (RVSS) starter. The reason you chose an RVSS for the application will have a direct impact on the selection of starting parameters. For example if you are using an RVSS to reduce line voltage drop during starting, you probably...