Before You Begin Menvier30Page 14Table 1. Voltage DropCurrentDrawnCable Length (Standard 7/0.2 alarm cable)10m 20m 30m 40m 50m 60m 70m 80m 90m 100m60mA 0.10V 0.19V 0.29V 0.38V 0.48V 0.58V 0.67V 0.77V 0.86V 0.96V80mA 0.13V 0.26V 0.38V 0.51V 0.64V 0.79V 0.90V 1.02V 1.15V 1.28V100mA 0.16V 0.32V 0.48V 0.64V 0.80V 0.96V 1.12V 1.28V 1.44V 1.60V120mA 0.19V 0.38V 0.58V 0.79V 0.96V 1.15V 1.34V 1.54V 1.74V 1.92V140mA 0.22V 0.45V 0.67V 0.90V 1.12V 1.34V 1.57V 1.79V 2.02V 2.24V160mA 0.26V 0.51V 0.77V 1.02V 1.28V 1.54V 1.79V 2.05V 2.30V 2.56V180mA 0.29V 0.58V 0.86V 1.15V 1.44V 1.73V 2.02V 2.30V 2.59V 2.88V200mA 0.32V 0.64V 0.96V 1.28V 1.60V 1.92V 2.24V 2.56V 2.88V 3.20V220mA 0.35V 0.70V 1.06V 1.41V 1.76V 2.11V 2.46V 2.82V 3.17V 3.52V240mA 0.38V 0.79V 1.15V 1.54V 1.92V 2.30V 2.69V 3.07V 3.46V 3.84V260mA 0.42V 0.83V 1.25V 1.66V 2.08V 2.50V 2.91V 3.33V 3.74V 4.16V280mA 0.45V 0.90V 1.34V 1.79V 2.24V 2.69V 3.14V 3.58V 4.03V 4.48V300mA 0.48V 0.96V 1.44V 1.92V 2.40V 2.88V 3.36V 3.84V 4.32V 4.80V320mA 0.51V 1.02V 1.55V 2.05V 2.56V 3.07V 3.58V 4.10V 4.61V 5.12V340mA 0.54V 1.09V 1.63V 2.18V 2.72V 3.26V 3.81V 4.35V 4.90V 5.44V360mA 0.58V 1.15V 1.73V 2.30V 2.88V 3.46V 4.03V 4.61V 5.18V 5.76V380mA 0.61V 1.22V 1.82V 2.43V 3.04V 3.65V 4.26V 4.86V 5.47V 6.08V400mA 0.64V 1.28V 1.92V 2.56V 3.20V 3.84V 4.48V 5.12V 5.76V 6.40VReducing Voltage Drop - Method 1:Double up the supply connections (12V and 0V),which will halve the resistance on each core andtherefore halve the voltage drop. When usingTable 1 to calculate the expected voltage drop,simply divide the voltage drop for a single core bytwo.Reducing Voltage Drop - Method 2:Supply the detection devices from the Aux outputon separate cores. This is the preferred method ofreducing voltage drop as detectors generallyoperate at lower voltages (9.5V). When using thismethod, the bus cable must have at least twospare cores.Remote Power SuppliesWhen you cannot reduce voltage drops bymethod 1 or 2, or the demand on the control unitpower supply exceeds its capacity (see TechnicalSpecifications –page 37), you should install one ormore remote power supplies. The supply musthave a "floating zero Volt rail" if connected to thebus, otherwise an earth fault will occur. Eaton’sSecurity Business recommends the EXP-PSU.When installing a remote power supply, fit it closeto the equipment it is powering.Figure 19 shows the recommended method ofconnecting a remote power supply.Figure 19. Connecting Remote Power Supply UnitsNote: Only two expanders can have zones on a Menvier30.Control unit Device 112V0V0V 12VBusDevice 2Remote PSUDevice 4Device 3