Recent content by rmarotta

Thanks for all the help. I'll be doing some investigation into all the suggestions presented. Getting sensors/reflectors closer together isn't an option, though. (There are actually four pallets abreast of each other, transported by the conveyor.) Upon exiting the hydro-cooler tunnel, pallets...

Mike, Thanks for your input. Lens condensation is a sometimes issue, presently cured with a quick wipe of the lens and/or reflector at the opposite side of the tunnel. What really causes the problem seems to be the occasional clouds of "steam" breaking the beam... even when the...

I'm using Allen Bradley 42MRU-5000 photocells that intermittently fail to operate reliably in a cold, high-humidity environment. The photocells detect pallets of cold vegetables on a conveyor coming out of a hydro-cooler tunnel. They stop the conveyor to await forklifts used to haul pallets...

Again, I do appreciate and understand your comments. I guess I will just have to figure it out on my own..... It still seems to me that conversion of existing analog & digital signals by an order of magnitude of 10 (2-20hp) cannot be that big of a deal. Thanks to all for your trouble.

I guess there's no way to determine the requirements of a particular drive without an intimate knowledge of it's design. What would be helpful is a component-level schematic diagram instead of simple block diagrams used for assembly/dis-assembly. Does anyone here know if such schematics are...

Okay, to be more specific: In my current project I want to run a 10hp 230/460v 3ph motor with an Allen Bradley 1336e series drive. The drive is rated 20hp but it's main control board is bad. It appears that all necessary signals are communicated via a ribbon cable between the main control...

Thank you, I appreciate your responses. I know this must be an odd request because I can't seem to find much info about it. In reading service manuals from various VFD manufacturers about their models and features, it seems they all do basically the same things with the controller end. Since I...

I'd like to use batteries to power the DC bus, and modify a small VFD to control a larger HP AC induction motor. Is there any DIY info available about how to "marry" a small VFD to larger capacity output devices? (ie: IGBTs rated for higher voltage/amperage.) Any help appreciated. Regards, rmarotta

Bill, Thanks for your interest! As I'm not an engineer, I'm curious about why (if all 12 leads are brought out of the motor windings) would the #7, #8, and #9 connections be "inaccessible"? Here's where I'm going with this... As I understand from various reading, an induction motor can be made...

Can any of these connections be used on a standard induction motor for use as a generator? (Perhaps using capacitors for excitation?) I don't care about efficiency, but if it's possible to do this, what could one expect? Regards, Rmarotta

DKirkham, Any progress in your quest yet? Here's a link to some serious horsepower coupled to a wheel for a little while..... http://www.killacycle.com Regards, RMarotta

Thanks for the input, jraef. You had it right in your 1) above. I guess I should have been more informative in my original post. The motor is used to drive a suspended rake/conveyor, which spreads crushed ice inside a storage bin. The load detector monitors power used by the rake to determine...

Thanks for the response. I have two drives actually. Both are Allen Bradley Cat.160 series. One is a preset model and the other is analog signal follower. The only useful output configuration I see listed for either is one that signals when the motor is running above a preset current. Won't the...

Gentlemen, I have a vfd that I'd like to use on a machine that requires a certain range of power to move material. Hopefully, this vfd will replace several components. (A reversing contactor, soft starter, and a non-functioning load detector.) Variable speed is not a primary requirement, but can...

Thanks all for your comments. I'm an A/C contractor in Florida, and I like to tinker. I thought I'd work on the unit at my home to see if I might increase it's efficiency. I have a 5HP/230V VFD and a 3HP/3ph compressor available to play with. Since available power is only single phase, I think...