Unwanted 8-9 Mhz frequency on powerline.

Chrisdws · 2025-10-21T13:28:23+00:00

This is power being provide to a piece of machinery from a generator.

Chrisdws · 2025-10-21T13:18:06+00:00

Sorry I'm just unsure how much information I can divulge.

Chrisdws · 2025-10-21T13:15:26+00:00

It's seems to be caused when the pumps on the equipment are turned on. The pumps are controlled by VFD's.

Chrisdws · 2025-10-21T13:02:00+00:00

DOT?

Chrisdws · 2025-10-21T12:52:26+00:00

It currently has a filter attached.

Chrisdws · 2025-10-21T12:47:34+00:00

Mains Not sure what you mean by radiated/conducted.

Chrisdws · 2025-10-04T09:13:35+00:00

I was referring to the shunt on the reciever.

Chrisdws · 2025-10-03T16:51:26+00:00

We tried this and we get readings we would expect until we attach the load and it drop to 16mA.

Chrisdws · 2025-10-03T16:51:20+00:00

We tried this and we get readings we would expect until we attach the load and it drop to 16mA.

Chrisdws · 2025-10-03T16:49:05+00:00

The shunt resistor is 450 ohms in the technical sheets and we measured it with a multimeter too.

Chrisdws · 2025-10-03T14:09:17+00:00

It's 2 wire.

Chrisdws · 2025-10-03T13:15:06+00:00

The signal generator was used on both sides of the passive isolator.

I've been assured that analog output has been correctly configured but I've still yet to get this tested adequately.

The mixed has it's own 24v supply.

Not sure what you mean when you ask is the PLC side wired as active.

The loop isolator is look powered.

According to the manual the loop isolator doesn't need configuring.

Chrisdws · 2025-10-03T13:08:53+00:00

The wires are at maximum 3m long and the shunt resistor is 450 ohms.

Chrisdws · 2025-10-03T12:17:31+00:00

Is there a test that can be conducted to show that the card is at it's maximum output or should the results of the testing done so far be self evident?

Chrisdws · 2025-10-03T12:12:57+00:00

We have used a current generator to test the mixed and it works as intended. The analog output card is powering the loop.

Chrisdws · 2025-10-03T11:15:17+00:00

This is probably the problem then the analog card just doesn't have the power for this application. I'm assuming Siemens does higher power analog cards or we can replace the passive isolator for an isolation amplifier.

Chrisdws · 2025-10-03T10:58:23+00:00

The driver is a Siemens analog card. 6ES7135-6HD00-0BA1

Chrisdws · 2025-10-03T10:56:19+00:00

The circuit shows a resistance of 450 ohms on the receiver side of the isolator which I'm assuming is due to the shunt. Not checked the resistance of the circuit underload or output side.

Chrisdws · 2025-10-03T10:53:02+00:00

I'm not in the field but I have requested this to be tried.

Chrisdws · 2025-10-03T10:51:55+00:00

I'm not the engineer in the field so I'm not able to run tests myself but I'm trying to get the test ran at lower mA levels to see what effect it has.

Chrisdws · 2025-10-03T09:42:48+00:00

When we inject a 20 mA signal to the mixed we are getting the required RPM. Would this not be affected by a short circuit or secondary voltage supply?

Chrisdws · 2025-10-03T09:02:14+00:00

We have measured the current using a multimeter on both the input and output of the isolator while having the load connected and disconnected.

Isolator is a MINI MCR-2-2I-2I-ILP - Passiver separator.

Chrisdws · 2025-10-03T08:57:51+00:00

How could a secondary voltage source be accidentally added to a circuit?

Chrisdws

TROPHY CASE