D&R Airlab User Manual - 22 Product Safety
Product Safety
Airlab from D&R Phone +31 294 418014, email:
info@d-r.nl
Page
73
22 PRODUCT SAFETY
This product is manufactured with the highest standards and is double checked in our quality control
department for reliability in the "HIGH VOLTAGE" section.
CAUTION
Never remove any panels, or open this equipment. No user serviceable parts inside. Equipment power
supply must be grounded at all times. Only use this product as described, in user manual or brochure. Do
not operate this equipment in high humidity or expose it to water or other liquids. Check the AC power
supply cable to assure secure contact. Have your equipment checked yearly by a qualified dealer service
center. Hazardous electrical shock can be avoided by carefully following the above rules.
PLEASE READ THE FOLLOWING INFORMATION VERY CAREFULLY
Especially in sound equipment on stage the following information is essential to know. Voltage and current
cause an electrical shock. Actually it's the current that causes the shock. In practice the higher the voltage
the higher the current will be and the higher the shock. But there is another thing to consider and it is
resistance. When the resistance in Ohms is high between two poles, the current will be low and visa versa.
All three of these; voltage, current and resistance are important in determining the effect of an electrical
shock.
However, the severity of a shock is primarily determined by the amount of current flowing
through a person.
A person can feel a shock because the muscles in a body respond to electric current. Current can also be
fatal when it causes the chest muscles to contract and stop breathing.
At what potential is current dangerous? Well the first feeling of current is a tingle at 0.001 Amp of current.
The current between 0.1 Amp and 0.2 Amp is fatal. Imagine that your home fuses of 16 Amp can handle
200 times more current than is necessary to kill.
How does resistance affect the shock a person feels? A typical resistance between your two hands "dry"
condition could be well over 100,000 Ohm. But if you are playing on stage your body is transpiring
extensively and your body resistance is lowered by more than 50%. This is a situation in which current can
easily flow.
Current will flow when there is a difference in ground potential between equipment on stage and in the P.A.
system. Please do check if there is any potential between the housing of the mics and the guitar synth
amps, which will be linked by your body on stage.
Imagine, a guitar in your hand and your lips close to the mic! A ground potential difference of above 10
volts is not unusual. In improperly wired buildings it can possibly be as high as 240 volts. Although
removing the ground wire sometimes cures a system hum, it'll create a very hazardous situation for the
performing musician.
Always earth all your equipment by the grounding pin in your mains plug Hum loops should be
only cured by proper wiring and isolation input/output transformers.
Replace fuses always with the same type and rating after the equipment has been turned off and
unplugged. If the fuse blows again you have an equipment failure. Do not use it again and return it to your
dealer for repair.
And last but not least be careful not to touch a person being shocked as you, yourself could also be
shocked. Once removed from the shock, have someone send for medical help immediately