Mobile Instrumentation & Control Panel

[dannym6]

Hello

I'm working in a project that involves an underground tunnel for mining. In the construction process the excavation team wants an panel with an RTU (remote terminal unit) sensor, and signaling, mounted in a mobile rack that could be close to the excavation team in order to monitor the gases concentration and turn on audible and visual alarms.

How could i keep with the regular electrical requirements (dedicated ground system, stabilized energy)if this panel will be in continuous movement day to day.

Thanks for your opinnion and time!

Danny Alarcón
Instrumentation & Control
GMI S.A.
Lima-Perú

 

[VEBill]

Why not use batteries?

I'm not an expert in what exactly would be required to "monitor the gases concentration and turn on audible and visual alarms", but it sounds like something that could be powered by a good Li-ion battery pack for the full duration of a shift or more. You'd need multiple units and recharging stations, and procedures and training.

Batteries might be a lot simpler than dealing with electrical power given the circumstances you've described. Use the electrical power at defined locations for re-charging.

 

[FreddyNurk]

When you state that they want an RTU, this is so that someone in a control room somewhere can see the sensor monitoring, right?

I can't see any other reason why portable gas detection facilities wouldn't be used.

That said, would it be possible to integrate it with whatever tunneling equipment is being used? I suspect you'll have to comply with whatever hazardous areas (explosive atmosphere) considerations relevant to the works.

 

[waross]

Check out Rig_rats.
These are common for protection of crews in the petroleum industry. Often during a shut down when several hundred men are working around the clock and pipes and vessels are being opened and vented, sometimes unexpectedly, the permanently installed gas detection systems will not provide adequate protection.
That's when the Rig-Rats are deployed. The configuration I see most often is a 'Rat powered by an extension cord with internal battery backup.
See

http://gasdetectors.conceptcontrols...as-4/rig-rat-iii-detectors?&bc=1858|1774|1784

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dannym6]

Thanks for your recommendations!

The tunnel will have a communication system via a leeky feeder system (

http://goo.gl/McC6e),

so this RTU (which have built-in I/Os and processing capabilities) will measure the gases concentration through the instrumentation, send it by the leaky feeder system (in VHF) to a station in tunnel entrance and from here with ethernet cable to PC station for monitoring.

If there is any abnormal situation the PC screen will show the alarm, so an operator can activate the visual and audible alarms located with the RTU, and also will call by a two-way radio system to he person in-charge inside the tunnel in order to evacuate the area.

The electrical team here is considering sending an extension cord, which with a right pack of batteries will cover the energy demand, but I'm also concerned about the Ground system, should I have a ground rod at the tunnel entrance and have the ground conductor installed like a cord extension up to the RTU location.

Thanks a lot!

Danny Alarcón
Instrumentation & Control
GMI S.A.
Lima-Perú

 

[danw2]

>so an operator can activate the visual and audible alarms located with the RTU,

That's wrong.

This is a safety system! It needs to trigger its own alarms! The operator can be busy, or distracted or bored reading magazines and texting his girlfriend. It doesn't matter. If people are down where the local RTU is, the local RTU needs to alarm a monitored hazard situation.