Manual

RevB MN301040 11of16
ELECTRICALINSTALLATION StepEight
WireLength‐Themaximumlengthofwireconnectingthetransmitterandreceiverisafunctionofwiresizeand
receiver resistance.Wiring should not contribute more than 10% of the receiver resistance to total loop
resistance.Forextremelylongruns(ov er 1000 feet),choosereceiverswithhigherresistancetominimizethesize
andcostofconnectingleads. Wherewiringlengthisunder100feet,wireassmallas22AWGcanbeused.
Wiring ‐ An external power supply delivering 10‐28 VDC with minimum current capability of 40 mA DC (per
transmitter)isrequiredtopowerthecontrolloop.SeeFig.Aforconnectionofthepowersupply,transmitter
andreceiver.Therangeofappropriatereceiverloadresistance(RL)fortheDC powersupplyvoltageavailable
isexpressedbytheformula:
RLmax=(Vsup–10V)/20mADC
 Shieldedcableisrecommendedforcontrolloopwiring.
 UsetheRedwireasthe(+)andtheBlackwireasthe(‐).

Fig.A
Wiring–ControlDrawing
