Ravica’s Sensor Controlled Relay – The Rosetta Stone?
Filed under: Data Center, airflow monitoring, environmental monitoring
A few weeks ago I talked about using the sensor controlled relay to turn on lights once an alarm had been triggered. In this blog I wanted to give another example of how versatile these units can be.
Solutions . . .
A great example is the solution that I found for a local amusement park. One of their outdoor venues was having an 
issue with their digital photography equipment overheating. It wasn’t economical to add air condition to the unit, so they needed to find a way to turn on multiple overhead fans automatically.
The management of this unit fell under the IT department, and the admin wanted to remotely monitor the data from his office (or any other portable device). The end solution was to monitor multiple environmental variables with the Ravica Sensor Probe and use the Sensor Controlled Relay to switch on the fan when the room temperature rises beyond the threshold level.
Since the sensor control unit has a user friendly web interface and an autosense feature, setting up the Sensor Controlled Relay is easy. The Sensor Controlled Relay can also be controlled via external computers, using the included SNMP command line utilities either interactively or programmatically.
From the unit itself, you can monitor the status of the Sensor Controlled Relay by four LEDs on the board. You can also monitor the unit remotely by using SNMP traps or the web interface, as well as e-mail and SMS alerts.
Implementation . . .
“The Sensor Controlled Relay provides 1 high-power SPDT 5V relay, with the maximum load up to 15A at 220 VAC. It includes Metal Oxide Varistors (MOVs) and Snubber circuits to protect the open contacts of the relays from high voltage spikes or noise transients. It monitors the power and load, and accepts a control signal, which is sent from the SensorProbe.”
We outsourced a local contractor to do the electrical work and the end result was better then we expected. Not only did we eliminate the equipment from overheating, but we are also able to trend the temp of the units over a given amount of time. This gave the admin a better picture of demand and heat generation.
Another thing to remember is the inlaid protection of this sensor. The Sensor Controlled Relay, it has a built in 16Amp circuit breaker and a 15Amp fuse (380 VAC, 125 VDC) giving it double protection for the external devices and possible damages by electrical fault. This assures protection for your sensor and your investment.
Conclusion . . .
As you can see, the Ravica Sensor Controlled Relay has many uses. It’s ability to control an array of analog devices makes it a versatile solution. It’s ability to monitor and protect itself make it a smart investment. That is why I recommend it every chance that I get.
- JimmyD
The future of data center design
Filed under: Data Center, environmental monitoring, humidity monitoring, temperature monitoring, water leak monitoring
I just read that the NSA is going to build a 20 acre data center in Utah. This one million square foot center will allow the NSA to decentralize its efforts and provide better security. Just imagine the amount of power it will take to operate a data center of this size? This Slashdot article points out that one of the biggest reasons why the 
government is building this compound is due to its power consumption and the current location’s inability to provide the needed electricity. The government estimates that it will use at least 65 megawatts of power or about the same amount that Salt Lake City consumes.
“The agency got a taste of the potential for trouble January 24, 2000, when an information overload, rather than a power shortage, caused the NSA’s first-ever network crash, taking the agency 3 1/2 days to resume operations. The new data center in Utah will require at least 65 megawatts of power” - Salt Lake Tribune
Another cool data center design is the one that Google is planning to build. The entire center will be built on a floating barge, and will use the waves of the ocean to help power the facility. It will also use ocean water to cool the equipment.
Last, but not least, is the underground data center in Sweden. This has to be the coolest data center ever! It is located underground, can withstand a hydrogen attack, has a waterfall and a greenhouse. It can generate its own power, and is equipped with triple redundancy Internet backbone access.
I wonder, what type of environmental monitoring sensors do they have? What type of redundancy and fail-safes? Designing a data center like these is a monumental task. I can’t wait to see what the future holds for Data Center Design.
- Jimmy D
Running a computer in a sub-zero environment
Filed under: Data Center, Intelligent Sensors, SensorProbes, environmental monitoring, temperature monitoring
I just saw a post on Slashdot that was asking the question, “How to Run a Computer in a Sub-Zero Environment?” Since network design is a passion of mine, this exercise interested me. It was a simple question, definitely not common. Even here in Maine, we are always trying to cool down our servers. I never considered someone might need to do the opposite.
Anonymous Coward (7548) gave us a real world answer. “Putting heaters (computers) in an environment meant to be cold is just adding to the cooling workload. If the computer is at any decent operating temperature, it’s going to be heating up the immediate surrounding area, and you don’t want that.” He advised people to mount the computer outside of the cold environment and put the sensor probes inside.
Although this appeared to be a sensible idea, the discussion added a new variable – building size. People were quick to point out that the original question required that he needed monitoring for a warehouse. Most warehouses are large, some larger then a football field. Clearly the above approach would not be applicable.
Embedding the PC inside of the sub-zero environment presents another issue – condensation. How are we going to protect the electronics?
BobPaul (710574) points out:
“Since cold air has a lower capacity to hold water, warming the air should decrease the relative humidity of the air, bringing you farther from the dew point and make condensation less likely. Just let everything sit in the cooler to get nice and cold before you turn anything on and I think it should be just fine.”
This response produced quite a bit of traffic. Quite a few people disagreed with BobPauls theory. Although this could be an answer, its validity is still in question.
The best solution to humidity was pointed out by Detritus (11846). He points out that “Military equipment often uses conformal coating, which is a spray-on plastic coating that protects the components from the environment.” This method encases the electronics protecting it from moisture. To the best of my knowledge, it doesn’t provide any thermal benefit, nor is it a life long solution. I would make sure to have a humidity sensor in the enclosure to ensure longevity.
The last post that I read made the solution clear. munpfazy (694689) writes, “For what it’s worth, we’ve always built room-temperature enclosures to house electronics gear and PCs for the work we do in Antarctica.” You can’t get much colder than that.
My conclusion, build small micro enclosures for the computer that includes the required environmental conditioning and monitoring equipment.
Let me know what you think . . .
- Jimmy D
Data center power outage alerting
Filed under: Data Center, Intelligent Sensors, environmental monitoring
We have already discussed the importance of monitoring temperature and humidity in the data center. Making sure that the investment your company has made into its networking hardware is well protected is paramount. However, normal temperature fluctuations are not the only potential danger to data room equipment. Power outages are another potentially hazardous event.
You’ve probably already placed UPS devices at the appropriate positions within the data center; which is the first step to protecting your investment. But if the power fails in the middle of the night and your UPS kicks in to keep your vital equipment running, how long will the battery backup keep your servers up and running, or better yet, your air conditioners and HVAC systems?
With the Ravica AC Voltage Detector, you can receive alerts when your systems switch to battery backup. Knowing immediately when your equipment is no longer running on line voltage can mean having the extra time to get a generator up and running or the core power issue resolved before batteries run out of juice and other systems begin to fail.
Temperature can even come back to bite us in this scenario. If your data room isn’t getting the proper cooling and ventilation, because the air conditioners or HVAC systems are no longer operational, you are now not only contending with power failures, but data center hot spots and equipment overheating as well.
The AC Voltage Detector is a simple sensor that works with any of the Ravica SensorProbe models. It detects voltage at 50 VAC to 250 VAC and runs on a open/closed contact switch system. You simply plug the cable into your UPS, like you would with any other piece of hardware. When the sensor detects the presence of line voltage, it reports a NORMAL status. When the power fails and the UPS switches itself on, the sensor automatically detects the change and reports an ALARM status.
Perhaps not every scenario calls for that extra line of defense, but when you consider the cost of data room equipment and the potential cost of that equipment’s failure, some extra measures to ensure its stability just make sense.
~ Jon Mills
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