Recent content by skrab

Hi Everyone, I need a low cost method to indicate rotary position of a cable winch drum. The wiring distance will be approximately 150 ft from the operator's station to the equipment. I am thinking about a simple series circuit just using a 24VDC power supply, fixed resistor, and linear pot...

I finally got a chance to look at the motor. It is powered via commutator. Also of note, this 3hp motor weighs approx 75lb and is built in a 215 frame. It is single voltage, single phase 115v. thanks in advance please more info on schrage motor, I've never heard that term. joe

I have a 3hp 1800Rpm 28amp 115VAC slip-ring type motor that I believe is a universal motor (3 wires marked CW, CCW and unmarked, no caps required, speed is proportional to voltage.) Nameplate says DYNA motor corp, Dayton Ohio. This motor was un-earthed from the obsolete motor bin. My guess is...

I originally posted the question pertaining to the change in current draw because of actual test report results I was being asked about. I apologize for not including this information in the original post, I was merely looking for an explanation of why no load current decreases when frequency...

Thanks Electricpete! With only the standard motor manufactures data (nameplate, PF, Eff etc.) is there any method to estimate the value of the increased current? joe

Hi Most posts regarding the performance of 50hz motors running on 60hz power and vice/versa have been concerned with the most important motor characteristics such as motor speed, torque output and efficiency. I would like to know the effect on no-load CURRENT when the voltage is the same but...

More application info: Believe it or not this is a new application. If it was up to me I would definitely go with a VFD. Time, cost and the ability for field adjustments all point to VFD. Unfortunately, the customer is mandating the wound rotor design. They believe the on-site maintenance...

Thank you again, electricuwe. I have 2 more questions. #1 Does anyone have any idea how to approach the timing of the acceleration? When we provide gradual acceleration to our cranes using VFD's we typically ramp up 0 to full speed in about 4-5 seconds. Would it be acceptable to design the...

Yes, Yes all information is helpful. My email address is: joeskrab@stratos.net thanks to all who comment.

Thank you very much, Electricuwe. I am indeed speaking of using magnetic contactors to switch out the starting resistors. Any information you could share would be greatly appreciated.

This is Skrab again. If anyone has ANY information regarding wound rotor control designs I would really appreciate it. Thanks in advance.

I need to design a control circuit and specify the components required for 5-step magnetic type starting of a wound rotor crane motor. The application is 380V 5HP 1500RPM. Could someone suggest a reference for calculations/conventions of wound rotor motor starting?

Does anyone have a good reference for practical wiring design in Class 1 and 2 hazardous locations? The NEC can be vague, incomplete and subject to multiple interpretations. Specifically, my questions are related to the controls of material handling equipment in which flexible cord is required...

Thank you jbartos. I would greatly appriciate it if you would forward the Meanwell info to me. Email: joeskrab@stratos.net

Manufacture is "Meanwell", model# S-25-24. Distributor is Jameco. Jameco (Cust. service/sales) is of no help. The spec sheet does include efficiency (80%), but the efficiency is given @ 100% load. Because I will at most use only 10% of PS output capacity, I discounted using the...