Hello All,
Recently a new Air Handler Unit was installed and it came with an 9 dedicated VFDs.
After the start up there have been constant issues where the first two weekends we had electrical over-current alarm, the weekend after nothing happened and this past weekend the Unit shut itself...
I have a situation where I replaced an older motor that was running a process along with a gear box and the set up was controlled with an ABB VFD, we have replaced the entire set up with a new high efficiency high speed (5500RPM) motor but the new motor is still controlled by the existing ABB...
I am faced with an undervoltage problem at work where some Air Handling and Exhaust Fan unit, while being fed through VFDs, are tripping breakers. The monitored voltage indicates an ongoing AB = 415V, BC = 417V and CA = 475V.
I am thinking that there might be issues with the VFD, control power...
If someone would ask you to explain (dummify) what happens in a distribution circuit during a fault, how would you explain it to them?
For a lot of people, it is very important to have certain concepts like faults broken down to simple terms using analogies, so please share your understanding...
Reviewing 110.26.A.1 and associated table the working space depth is clear on its requirements.
However I have been told that if you have two switchboards facing each other at 600V where one of the boards is 3000A and the other is 800A, you have to double the working clearance. As for the...
A contractor sent an RFI (referring to 430.31) indicating that VFDs that are coming with AC units must have fused protection.
I am providing just feeders as requested by mechanical engineer, to single point of connection, connecting to VFD which has an integral disconnect.
it seems as if the...
I have been asked to look into using a natural gas engine generator vs diesel engine, 1000kW for hospital use.
By the manufacturers I was told that the NG is a lot more expensive and it needs to be a lot bigger to provide the same power as a smaller diesel engine gen.
I am on an OSHPD project...
