GAI-Tronics 700 Series 24 V DC Page/Party Systems - Manual (Page 4)

Pub. 42004-140E
Installation of GAI-Tronics 700 Series 24 V DC Page/Party
®
Systems Page 4 of 13
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08/13
Installation Procedure
Step 1 — Electrical Noise Considerations
When planning your system, consider the following suggestions to avoid electrical noise caused by slip
rings and silicon control rectifier (SCR) power supplies.
Slip Rings.
Use a radio frequency (RF) alternative and avoid using slip rings as audio conductors. Slip
rings are a source of electrical noise and are not reliable.
SCR Power Supplies.
If the Page/Party ® system is being installed in areas where SCR power supplies are
used to power motors or other heavy equipment, consider using one or all of the following four
recommendations to reduce electrical noise.
1. Separation—Locate the Page/Party ® system cables as far as possible from the SCR power supply
input or output cables. Electrical coupling between cables is reduced by the square of the distance
between the cables.
2. Shielding—Use shielded (armored) system cables if the cable must be run in the same bundle or cable
tray with the SCR power supply cables. Shielded cables reduce capacitive coupling between SCR
power supply cables and Page/Party
® audio cables.
3. Fiber Optic Cables—Use audio cables with fiber optic cables in cable trays as an alternative to
shielded cables. Fiber optic cables are immune to SCR-generated electrical noise.
4. Isolation—In 24 V dc systems, the battery/battery charger usually provides isolation from the SCR
noise on the ac power system. Cable separation and shielding as mentioned above still apply.
N OTE : Avoid battery chargers that use SCRs in their design.