What would be the consequence of inadvertently rolling lead 1 and 4 for example on a 6 lead, wye connected induction motor assuming 1, 2, 3 were the phase leads and 4, 5, 6 were the neutral point.
The new configuration would be 4, 2, 3 phase leads and 1, 5, 6 neutral. This is probably a simple...
In the USA, what are the regulatory standards to reference when applying hazardous location requirements to automotive vehicles, for example?
NFPA 505 is as close as I can find, but this applies only to special purpose industrial trucks and specifically not automotive vehicles.
Intuitively...
I have searched the web and thought I found a resource but they only have the cover image for the manuals, not the whole pdf. If anyone can provide curves or information about any (or all) of the following ITE documents, it would be greatly appreciated.
Various TCC curves for the K series...
I need the most effective way (using one device) to communicate between two devices; one using MODBUS RTU protocol over multi-mode fiber, the other using TCP/IP over CAT-5 copper. Is there a media converter that does it all in one package?
In V/Hz mode with a transformer coupled load, can say a bank of resistive heaters be fed? If so, what type of load imbalance could it handle?
The VFD is "free" and a new SCR controller will cost as much, or more than a simple VFD.
We have an old GE street lighting transformer (constant current regulator) that has been in the shop about once per year for various failures. It is presently at a repair facility with orders to upgrade the control scheme. The technical personnel there is familiar with these regulators, but...
A while back, I was watching a program on one of the "Learning Channels" that mentioned evidence of Earth's magnetic field reversals (several) oberved in lava deposits on ocean floors.
If these reversals really did happen, it couldn't have been instantaneously for each event. Did it take...
What is the best arrangement for a single zone of multiple parallel heater probes from a load balance perspective on the SCR controller? The application is as follows:
* 6-SCR,3-phase,480V controller, phase angle fired
* 112.5KVA, 480V Delta - 100V Wye (58V ground), 3-phase encapsulated...
Background:
We have a 3500HP extruder motor that has been re-rated with a 1.40 service factor. The stator windings run cool, but is rotor limited beyond 1.40 loading.
A project is coming along to marginally increase the rates this machine must run. 10% increase in loading is expected after...
Background:
We are purchasing a 200KW genset for standby service duing a natural disaster at our plant. The genset is purely for logistic functions for making facility repairs before the utility can get back online. The bulk of the required loads are on one 480V substation, but there are...
For a hypothetical situation, would it be possible to connect two 3500HP induction motors (drive end into non-drive end on dual shafted motors) both with identical nameplate ratings to load share a 7000HP load?
Assume the final output shaft can handle the torque requirements. I've heard of...
What is the basis for large motor t-lead sizing? We have a 7000HP, 4000V, 900FLA motor that had to be rewound. During the repair, parallel 4/0 conductors were used per phase. The motor originally had 3/0 conductors. This seems like it would but a large thermal load on termination lugs for...
We have an application with an 81KW heater bank controlled by a 480V 3-phase SCR controller. Each heater probe is 240V, 750W, 1-phase. The probes are connected in series-delta; 2 probes in series per delta leg, 18 parallel legs for 108 total probes.
We are experiencing several failure modes...
Over the past several years, our industrial facility has experienced many electronics failures where the root cause has been capacitor failure due to electrolyte dry-out. The problem has been seen in power supplies for PLC's, protective relays, and process control equipment installed in the...
Over the past several years, our industrial facility has experienced many electronics failures where the root cause has been capacitor failure due to electrolyte dry-out. The problem has been seen in power supplies for PLC's, protective relays, and process control equipment installed in the...
Over the past several years, our industrial facility has experienced many electronics failures where the root cause has been capacitor failure due to electrolyte dry-out. The problem has been seen in power supplies for PLC's, protective relays, and process control equipment installed in the...
We are looking to develop some sort of awareness training package for area classification for maintenance and operations personnel. If there are any computer based or powerpoint packages anyone knows of for sale or otherwise, could you please refer me.
Our facility has both dust and vapor...
A while back, a large process control room UPS (20kVA ferroresonant, continuous online, 1-phase 120V output) lost it's phase relationship and dropped out of synchronizm with the maintenance bypass frequency and began freewheeling.
While freewheeling, all lighting and analog instruments in the...
For example a large synchronous motor rated 14,000HP @ 0.85 leading PF.
What would be a good way to approximate maximum HP output at say 1.0 PF and 0.85 lagging PF?
What is a general rule of thumb for coordination timing between the time-overcurrent clearing for main and tie breakers operating in a spot network configuration? If I add 0.3 seconds for every downstream device on our 13.2kV feeder, clearing time becomes significant at the mains.
This is our...
