BYAN SYSTEMS, INC.
Automated Gate and Access Control Products
413 Linden • Lusk, WY 82225 • (800) 223-2926
21
LOOP DETECTOR CONNECTIONS
THE MOLLEX CONNECTOR HAS 11 WIRE LEADS 12 INCHES LONG. THE PIN OUT IS
AS FOLLOWS:
RED
- POWER B+
BLACK
- POWER B-
BLUE
- RELAY A COMMON (PULSE OR PRESENCE)
ORANGE
- RELAY A NORMALLY CLOSED (PULSE OR PRESENCE)
YELLOW
- RELAY A NORMALLY OPEN (PULSE OR PRESENCE)
GREEN
- RELAY B COMMON (PULSE ONLY)
PURPLE
- RELAY B NORMALLY OPEN (PULSE ONLY)
BROWN
- LOOP WIRE
GRAY
- LOOP WIRE
WHITE
- NOT USED
NOTE:
LEADER WIRE FROM THE LOOP, WHETHER IT IS PREFORMED OR
MANUFACTURED ON THE JOB SITE, MUST BE TWISTED A MINIMUM OF FIVE
TURNS A FOOTS.
THE PROPER LOOP WIRE
WHY IS THE LOOP WIRE SO IMPORTANT?
ONE OF THE MAIN CAUSES OF VEHICLE
LOOP DETECTOR FAILURES IS THE USE OF INFERIOR WIRE TYPES WHEN CONSTRUCTING
THE LOOP. SINCE MOISTURE CAN CAUSE A SIGNIFICANT CHANGE IN THE DIELECTRIC
CONSTANT OF THE INSULATION, WHICH RESULTS IN EXCESSIVE LOOP (FREQUENCY)
DRIFT, YOU MUST CHOOSE A WIRE WITH AN INSULATION THAT IS MOST IMPERVIOUS TO
MOISTURE. IT IS ALSO IMPORTANT TO CHOOSE A WIRE WITH A RUGGED, ABRASION
RESISTANT INSULATION. REMEMBER THAT ALL PAVEMENTS ARE POROUS AND
CONTAIN TRAPPED MOISTURE. WATER OR OTHER CHEMICALS WILL EVENTUALLY
REACH THE INSULATION AND EITHER ATTACK THE INSULATION, BE ABSORBED BY IT,
OR MIGRATE THROUGH TINY CRACKS IN THE INSULATION AND CHANGE THE
DIELECTRIC OR BREAK DOWN THE INSULATION AND CAUSE SHORTS TO GROUND.
WHAT ABOUT THE WIRE?
POLYVINYL CHLORIDE (PVC) INSULATION (TFFN, THHN,
AND THHN-THWN) SHOULD BE AVOIDED SINCE IT TENDS TO ABSORB MOISTURE AND
CRACKS VERY EASILY. THE INSULATION IS THIN AND VERY SOFT, LEAVING IT
VULNERABLE TO DAMAGE DURING INSTALLATION AND RAPID AGE CRACKING AFTER
SEALING. ANY ONE OF THE ABOVE MENTIONED WIRE TYPES HAS ONLY 0.015” OF
INSULATION FROM12 GA. TO 18 GA. IF THERE IS ANY DOUBT ABOUT IT’S
VULNERABILITY, CRIMP THE INSULATION WITH A PAIR OF PLIERS AND SEE HOW IT
CRACKS. SEE HOW EASY IT STRIPS WITH A POCKETKNIFE. WHAT WOULD AN
