I am having a problem with a Siemens Hydroranger 200 with 4-20mA outputs. About every two weeks or so we will have one of the 4-20mA outputs go out and have to go to the second set of outputs. After the second set goes out, we have to replace the whole unit. We have surge suppression with proper grounding on 110 vac and 4-20mA lines. The only I know left is to replace the wiring. The output on the Hydroranger goes straight to an AB slc500 analog input module. Any thoughts??

 

Have you talked to Siemens? Something is clearly wrong... and it is unlikely to be the meter itself from your description. It would be best to get a Siemens field engineer onsite if you can.

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Interesting, most analog problems manifest themselves on the input side, not the output side. How many times has this happened? Just the once, to one unit?

Have you contacted Siemens? I wonder if it isn't a bad lot of A/Ds or something in the circuit.

There are a couple models of HydroRanger. My experience with several installations has been that the HydroRanger 200's dual analog outputs are well designed, industrial grade, isolated, active (powered) current outputs. I haven't encountered this issue in several installations.

I'd speculate that somehow the AOs are seeing excessive voltage, but I can't imagine why the input side wouldn't manifest a problem with any spiking, ground loops or excessive common mode that the output sees.

Are you running high voltage wiring in parallel with the AO cabling to the AB? VFD wiring? Switched AC voltage wiring? The manual recommends shielded, twisted pair, grounding only one end of the shield. Is that the case?

I'd appreciate it if you kept this forum informed of whatever discovery or resolution you come to.

Issac Issachar

 

Did anyone sort this issue as i am having a similar issue a Hydroranger 200 dual unit going into a SLC500 A/D the outputs will be fine for a month then one will drift for up to an hour then resume the correct level, it is not always the same output that drifts.

Ultrasonic heads have been renewed cabling to the heads has been renewed the controller has been changed.

when we have been on site when it happens the display changes so it's not the A/D card.

We have this at a couple of sites Siemens seem disinterested at best.

 

Siemens has a single channel ultrasonic level unit, the LUT400, which I saw a month or two ago.

Its 4-20mA output is a new design; it can be either an active output, powered by the LUT, or a passive output, powered by an external DC power supply.

The Siemens guy was with the local rep and lit up when I complimented them on this neat feature, which could go a ways in eliminating or reducing ground loop issues.

He went on to say that LUT had been redesigned for greater EMF noise immunity/rejection. Apparently, cross talk and electrical noise pickup in the vicinity of VFD's and their wiring can cause a problem in the ultrasonic box.

I hadn't seen that but you might want to look at wire/cable routing and shielding of any feeder lines from VFD's and/or shielding.