Alpha Communications STR QwikBus Installation, Programming, And User's Manual page 5

Are you running new wire or using existing wire from a previous system?
Although digital systems are fairly forgiving in wiring requirements, they are still
susceptible to RFI from unusually strong nearby transmitters, EMI from electrical lines
running nearby, or existing wiring that is not twisted, in poor condition, or not a suitable
gauge. Please refer to the wiring thickness chart below to determine the minimum
recommended wire gauge needed. If the existing wiring is more than 12 years old, has
deteriorating insulation, questionable splice connections, corrosion, or is not configured as
twisted pair wiring, it is highly recommended that new wire be run.
To reduce the risk of interference problems:
 Always use a single twisted pair wire for the two wire BUS line.
 Do NOT double wires to increase effective wire diameter. This will cause interference
problems.
 Do NOT install any unused additional wires with open ends.
 Never connect the shield from a cable, or connect the shield from one cable to
another.
 Use a separate cable to the door strike from the SP333.
 Only use a 12VAC door strike or 12VAC relay with less than 1 amp draw.
 If it is absolutely necessary to run the door strike wiring in the same cable as the BUS
line, you must use a transient voltage suppressor at the door strike end.
 Loop resistance should be less than 20 ohms.
Cat5, Cat5E, Cat6, and the new Cat7 spec. wire is NOT
How many risers will you be using?
The recommended maximum number of monitors on a riser is 10 with each riser originating
from the VSP333-2 Control Unit, including from the EVB333 Amplified Splitter(s) if your
system requires them.
For technical assistance and help determining equipment needed please call:
Alpha Communications® at (800) 666-4800 Monday – Friday 8:30- 5:00 pm
Twisted pair is always recommended.
3
recommended.