DKstuf CCTV

Your Online CCTV Deals 3993 Bayless Ave. 314-828-6036

In Store & website Return policy

There is a 30 Day Only Warranty in house for all Items.

(Warranty does not cover the expense of removal or reinstallation of products or any damage or injury to property or persons resulting from the removal or reinstallation of products)

All Manufacture Warrantees must be handled thru the Manufacture. So Please fill out and mail any Warranty Cards Enclosed with items. Any items returning must be in original Packaging for retail sale. Any Items Returned for compatibility issues or Just because didn’t use or other. There will be a 20% Restocking fee. DUE TO THE VERY LOW COST OF OUR PRODUCTS: No Returns will be accepted after 30 Days for any circumstances! Dvrs & Dvr Cards we also strongly suggest checking occasionally with Manufactures Website in Manual for Firmware upgrades!

Lightning or improper voltage connection or power surges are not covered at all! We strongly suggest purchasing a good surge protector to protect your equipment! It is sensitive electronics and very susceptible to power fluctuations and surges.

(Familiarize yourself with your equipment. Such as if you have a 24 volt AC system or a 12 volt DC system & Power Supply. failure to do so will result in Damage to equipment & Cameras and are not returnable for this mistake. 1 Second of incorrect voltage will do severe Damage to Cameras sensitive circuit Boards.)

We also highly recommend if not sure or not comfortable with doing installation yourself, we suggest you hire a qualified installer.When Hiring any Installer ask lots of questions such as what is there warranty and what do they cover or charge for follow up calls? What is their warranty period. Dkstuf is a Supply House only and we do no installs  So we highly recommend asking Any Installer prior to hiring lots of questions.

Sincerely Dkstuf

Tips for WHAT YOU CAN Try To DO ABOUT LIGHTNING STRIKES

and

HOW TO PREVENT DAMAGE TO CCTV COMPONENTS

Protecting a CCTV system and it components from lightning damage does not use the same methods used to protect human life from electrical shock. In fact many of the techniques used to protect humans from lightning also cause some other problems in the CCTV system.

 

First of all, nothing can prevent a direct lightning strike. The result is usually a smoking melted down blob of carbon and metal. However, if the lightning strike is somewhat off center or just nearby, then there is a chance for electronic equipment to survive, provided certain precautions have been taken to protect the electronic components from over-voltage and over-current. These two things cause electronic equipment to fail.

If you read up on the subject the first thing you learn from the various books on the subject of lightning protection is that you need to "GROUND EVERYTHING". This process creates as many paths to ground as possible to bleed off current from the strike and keep the destructive voltage from rising to high.

From a human protection point of view this is good solid advice, but from the CCTV equipment point of view this is very hard on the equipment and can reduce the lifespan of the equipment to the first occurrence of a lighting storm.

The "Ground Everything" advice is designed to protect people from electric shock and should be followed wherever possible. But what you must do to protect equipment from damage is very different.

Lighting Protection in the form of diode and gas tube lighting suppressors need to be installed at one end and maybe both ends of any long cable run. The long cable runs are more prone to voltage build ups due to local lightning static discharges.

When lightning strikes from cloud to cloud or from the upper atmosphere to the ground, a differential charge appears on the ground. Since the charge is not equal at all points on the ground, this differential change will cause current the flow down any conductor connected to both grounds. This current flow can be thousands of amperes occurring for only milliseconds, but in that short amount of time the current causes a sharp rise in the voltage that can reach thousands of volts. Your CCTV equipment is not designed to withstand that kind of voltage at the video input and output terminals, so the equipment gets permanently damaged.

For safety sake you should install lightning protection on your video cables but be sure to BOND EVERY LIGHTNING PROTECTION DEVICE with the LEAST POSSIBLE INDUCTANCE TO MINIMISE THE AMOUNT OF VOLTAGE THAT WILL BE DEVELOPED BETWEEN THEM WHEN THE LIGHTNING DOES STRIKE. Even a few inches of #l6 wire is enough to generate up to 300 volts or more at the video input frying the video system when lightning strikes, (not because of the resistance of the wire but because of the inductance of the wire connecting the lightning protection unit to the ground).

A lightning strike is a very short duration event, and so the signal it creates has very high frequency content, this is why the inductance of the connecting wires, not the resistance determines the effectiveness of the lightning protection device.

Even a very small inductance on the order of one or more nano-Henrys is capable of generating very high voltages between the video equipment and the lightning protection devices during a lightning discharge. The ground wires on the lightning protection devices should be as short as possible. Do not add extra wire to the ground wire to extend the connection, instead route the video cable over to the lightning protection device mounted as close to the ground as you can so that the ground path for the current will be as short as possible.

There is one more thing to consider when using lightning protection. Lightning protection requires a good ground to function. That ground can induce ground loop artifacts into your video signal. Now that you have protected your video equipment with the lightning arrestors, you may discover that you now have a ground loop in your video image. This ground loop is created by the normal ground at the DVR or Monitor and the new ground applied by the lightning arrestors. This will look like black or translucent bars on the video image. These bars can stand still or move slowly up the screen. When the bars reach the top of the screen others will appear at the bottom of the screen to take their place.

Since you cannot remove one of the grounds to eliminate the ground loop it may be necessary to install ground loop blockers to finish the system. The ground loop blockers will remove the interfering signals created by the lightning arrestors and the arrestors will protect the system from lightning strikes. The ground loop blockers are available from  Dkstuf.com.

Remember, grounding is for electrical shock protection purposes.

Lightning arrestors reduce damage to electronics from lightning.

You can’t avoid equipment damage from a direct hit.

Both bonding and grounding conditions must be met

to protect both people and the equipment.