Recent content by EEAutomEng

Scotty, I have 4-poles on the relay, if the relay's thermal current rating is 10 amps does that mean each pole can carry 2.5 amps each indefinitely?

Please forgive me for I am new to the electrical industry... The NEMA ratings for the relay contacts show "Thermal Continuous Test Current" and then there is make / break current. The break current is much lower than the thermal. Can someone explain the...

They're for interlocking a clutch control circuit (relay logic) of a mechanical power press to a robot. The contacts are switching solenoids and other control relays, not motor loads. I contacted the mfg of the relay and they said the same thing as dpc.

Can someone explain a reason why putting 2 contacts in series would increase switching ampacity?

We have an 8-motor/3-axis machine which, in essence, is a robot as far as the RIA standards go. The controls for the machine include a teach pendant with 2 jog buttons, a 2-channel e-stop button, and a 3-position enabling device. My question is what makes the circuitry for the 3-position...

We have an 8-motor/3-axis machine which, in essence, is a robot as far as the RIA standards go. The controls for the machine include a teach pendant with 2 jog buttons, a 2-channel e-stop button, and a 3-position enabling device. My question is what makes the circuitry for the 3-position...

What is the voltage supply to the UPS and how many VA do you need to "back-up"? If you're powering a critical load, then your best bet would be to use an "On-Line" UPS. If you need more info I have some literature that I can send. And NO, I am not a salesman.

cvtem, FrancisL had a very good point. The real keys to learning ladder logic is to understand how the PLC scans the rungs and to understand the data structure. Understanding the data structure will help you understand the instructions (normally open, normally closed, one shots, timers, latches...

Wendy, check out the ANSI B11 standards. They may apply to your specific application.

I have heard different recommendations on methods of grounding when it comes to PLCs. What type of fasteners should I use when connecting the equipment grounding conductors to the ground bus? I have heard recommendations for zinc-plated screws and star washers. Can anyone offer a detailed...

I just did a project with ControlLogix and our customer had us use their plant standard. Dogleg had a good point. Try this: "Local:3:I.Data.7" would have a wire tagged as L:3:I.07

I have wired this circuit before when I first learned panel building, but never understood why it was done. Typically, a control transformer would be mounted on top of the enclosure and the push-to-test pilot lamp would be mounted on one of the doors of the enclosure. The neutral from the...

It is connected to the secondary of a 1.5 KVA transformer. Voltage is 120 VAC 60 HZ. The neutral (X2) is grounded.

Forgot to add something...nothing I could find in NFPA 79 that says anything about this.

We manufacture industrial automation that is asscociated with mechanical power presses and we have a customer who has a specification that reads "A suitable detector lamp shall be provided to verify ground continuity. The pilot light shall be a transformer push-to-test." Is this a code...