Some of the main topics in this chapter are
Hardware gets destroyed or corrupted far more often than necessary because most of the time it's preventable. Certain individual devices in computers (such as hard drives and modems) are more susceptible to damage than other devices, and you have to create an environment that protects them.
One of your biggest enemies is your local power company. Another one is Mother Nature if you live in an area that has electrical storms. There are, however, some remedies and safeguards you can employ to help offset the potential damage caused by these two entities.
Whenever the subjects of hardware and electricity come up, I hear users say, "I have a surge protector." My answer is, "Big deal, so what?"
Let's talk about surge protectors by taking a quick overview of the different devices people purchase and what they can do for you (or fail to do for you):
No surge protector will protect you from the effects of a direct hit of lightning. No matter how much you spend on the fanciest surge protector in the world, it's not going to defend itself or your computer against a million volts.
If you work in an office building with adequate protection against direct lightning hits, the odds are pretty small that the electrical outlet that controls your computer will blow. If you work in a small building or at home, then you need to take precautions.
There's only one real defense against serious lightning strikes--pull the plug out of the wall. If a lightning storm is raging, unplug. If a lightning storm is expected, unplug before you leave for the day.
TIP: Except during storms, it's okay to keep a computer running all the time. Most computers that are never turned off never have CMOS battery problems, their hard drives last longer, and the power supplies rarely need replacement. Just make sure that you can hear the fan.
It's been my experience that the majority of computer systems destroyed by lightning received the fatal surge through the telephone lines connected to a modem.
I've seen more than a few networks brought to their knees from an electrical hit taken by a modem attached to one of the workstations. The surge went through the modem, through the serial port, to the motherboard, where it found (and fried) the NIC. The NIC sent the surge through the network cable, spreading the zap to every card on the system. Some of the NICs pushed the surge to their own motherboards.
The fact is that most electric power companies protect their lines. There are lightning arrestors, or other types of protection, at each transformer. Almost no telephone companies in the United States use any form of line protection. Because telephone lines conduct electricity, if one line gets charged with high voltage, it just sizzles and burns whatever is in its path. If you're using surge protectors, be sure to purchase the type that includes protection for telephone lines--one end of the strip has a phone line jack. For real protection, make sure that you pull the telephone line out of the wall jack when you're preparing your defense against electrical storms.
Also, telephone system installations should include protection for the lines as soon as they enter the building. Passing the lines through a gas plasma protection device will help defend them.
While you're protecting your computers by considering surge suppression, remember to protect yourself--stay off the phone during a severe lightning storm. Think of your ear as a modem and your brain as a motherboard.
The need for a surge protector arises only a few times a year for most people. The number of times voltage rises high enough to damage computer equipment is minuscule compared to the number of times the voltage is low. Most people encounter low voltage at least once a day without knowing it.
A line conditioner is an inexpensive way to regulate the voltage coming into your computer. It takes the power coming out of the wall, measures it for voltage, and then pushes voltage up if it's too low, or brings it down if it's a little too high (it cannot defend against a real high voltage zap). Line conditioners are sold by wattage, and a 600W unit (sufficient for most computers) is less than $100.
Low voltage (called a brownout) destroys electronic equipment. Well before you see lights flicker (a sure sign of a drop in voltage), your hard drive feels the damaging effect of low voltage. Bad spots on a drive, cross-linked files, and even lost clusters can often be blamed on low voltage.
Your computer's power supply can have its life shortened by continuous low voltage, as can the power supply on your printer or scanner or any other peripheral. Whenever there's a problem with low voltage, there are two entities to blame--the local power company and computer users.
Your local power company generally tries to put out enough power to maintain the optimum of 120V. But certain times of the day or certain weather conditions can make this difficult. As a result, most power companies consider anything within six percent of the optimum to be totally acceptable. Don't worry about voltage as long as it's between 105 and 125V.
The truth is that 105V isn't a terrifically safe voltage for computer hard drives, or even for many motor driven devices in homes and buildings. And, 125V can be troublesome for electronic devices. Any further deviation higher or lower becomes a severe problem.
To make matters worse, the electric power company has two other hurdles to leap in its effort to provide 120V to you:
Other voltage problems occur because users fail to pay attention to common sense, technical specifications, and advice from experts. If you create a situation in which your computer is not getting enough voltage, you have to correct the condition or use a line conditioner to overcome the problems you've created.
Laser printers belong in dedicated outlets, and so do copy machines or any other pieces of equipment that pull a lot of amps and need a lot of voltage. Never put your computer into the same outlet as a laser printer. If you only have one outlet available, put a line conditioner into one plug and attach the computer and monitor to it. Do not plug a laser printer into the line conditioner.
If there are low voltage problems all over office (there are many ways to measure voltage, including methods of tracking voltage over a long period and printing the resulting voltage chart), it might be easier and cheaper to put line conditioning onto the source of power--the breaker box. Intelligent line conditioners are available that serve this purpose. Intelligent means that they read the voltage and only correct it if necessary. Dumb line conditioners also exist that raise voltage without measuring first, but these line conditioners aren't safe.
Some office buildings have transformers that feed the building or multiple transformers that feed specific parts of the building. And some of these transformers can be adjusted to raise the voltage. This process is called re-tapping. It's dangerous. Don't do it. Some electricians think it's a nifty and fast solution, but it's not. It's not a good solution because it's a permanent solution to a temporary problem, and applying the solution when the problem goes away is dangerous.
For example, suppose that you measure the voltage every day and you come to work and see that you're getting 106V out of every wall outlet. It makes sense to think you should push the voltage up about 12 points. That brings you to 118V, still under the 120V optimum, but close enough for your hard drive to stay happy.
Then, on Saturday and Sunday, when the elevators aren't running much, most of the copy machines are turned off, and all sorts of other electric gizmos such as coffee pots and popcorn makers aren't pulling on the electrical resources, the voltage coming out of the box is the expected 120V. However, the voltage feeding your running file server is 132V. This can turn the motherboard, hard drive, and all the devices in the computer to toast.
An Uninterruptible Power Supply (UPS) is a necessity on a network server or a computer used for mission-critical applications. It's almost a necessity for every computer, even if the entire company won't halt if a particular computer goes down. The danger of corrupted data is an annoyance at best and a revenue risk at worst. Luckily, the price of UPS units has come down to the point that it isn't extravagant to purchase enough UPS units to keep all or most of the computers in any office running when the power fails. The two basic types of UPS units are as follows:
Two features are available with the On When Needed UPS units that you might want to consider:
The On When Needed UPS unit is the one generally found attached to PCs, and we'll assume that it's the type of UPS you're planning to install on your Windows NT Server. We'll also assume that you've purchased the communication cable (otherwise, it's just a battery and needs no Windows NT configuration).
The physical installation is quite simple--plug the UPS into the wall and plug the computer and monitor into the UPS outlets. Follow the manufacturer's instructions for connecting the cable between the UPS and one of the computer's serial ports. If you're using a serial mouse and an external modem, you'll have to add a serial port to your computer or switch your mouse to a mouse port type.
To tell Windows NT Server about the UPS:
You can configure the UPS for varying levels of features and tasks through the UPS dialog box.
Select the Power Failure Signal check box if your UPS unit has the capability
to send a message if the power fails. To your serial port, this message is the same
as a clear-to-send (CTS) signal.
Select the Low Battery Signal check box if your UPS unit can issue a warning when the battery power is low. To your serial port, this is like a data-carrier-detect (DCD) cable signal.
Select the Remote UPS Shutdown if you want the UPS software to enable shutdown through a remote computer. To your serial port, this is like a data-terminal-ready (DTR) cable signal.
3. For each item you selected, specify UPS Interface Voltage, either Negative or Positive, so that the serial port can communicate properly. The documentation that was packaged with your UPS system provides this information.
4. Select Execute Command File to have the system execute a command file just before the system is shut down. This is a useful option if you want to make sure that certain events occur before shut down. For example, you might want to log off a network or close another type of connection.
The command file is installed or written by you and must have a file name extension of BAT, EXE, or COM.
The command file must be placed in the \SYSTEM32 directory under the system root directory. For most computers, this means the path is \WINNT\SYSTEM32.
The command file must complete its program execution in less than 30 seconds to ensure that it runs before shutdown is complete.
5. Enter the name of the command file in the File Name box.
6. In the Expected Battery Life box, specify the number of minutes that the system can run on battery power. The available range is 2-720 minutes.
7. In the Battery Recharge Time box, specify the number of minutes it takes to recharge the battery. This number is the number of recharge minutes needed for each minute of battery runtime. The available range is 1-250 minutes.
8. In the Time Between Power Failure box, specify the number of seconds that should elapse between the failure of power and the first message notifying the user. The available range is 0-120 seconds.
TIP: You don't have to set the Time Between Power Failure number to a short interval; it's not necessary to be notified the moment the power fails. Most power failures last less than a minute, so you just keep working. Besides, the UPS probably beeps.
10. Choose OK when you have finished entering data in the dialog box. The system then checks your UPS device to make sure that the communication between the serial port and the UPS works.
If, for some reason, you don't want to use the Windows NT management features with your UPS, open the UPS dialog box and deselect Uninterruptible Power Supply Is Installed On.
The physical installation and configuration is followed by the startup of UPS services. To accomplish this:
You have to tell the system how you want to launch the UPS services you've installed.
Select Automatic to have the service start automatically every time you start your system.
Select Manual to start the service yourself after the system is up and running. To do this, go to the Services dialog box, highlight UPS services; then click Start.
Select Disabled if you don't want the service to start.
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