WaveWare Apollo T-2000 Informações Técnicas descarregar pdf (Página 31)

Certification Manual

- 31 -

Voltage Drops

One consideration of running wires is the length of the wire run and

how much voltage drop will occur. Because our systems are low voltage

systems, voltage drop is important to consider. The Alliance AllCall©

Nurse Call Project Manager has usually provided the appropriate wire in

order to make installations easier. Because we have done these

installations numerous times, we have already figured out the type and size

of wire that are usually needed for specific jobs. For example, CAT5E

cable is more than sufficient for most bus line applications. However, if the

run is longer than 1000’, Alliance specifies un-shielded 18/4.

However, should you encounter a situation where there is doubt, it is

important to know how to figure voltage drop. There are a couple of ways

to do this, but we will use the formula below to calculate voltage drop.

There is also a table that gives resistance of common gauge copper wires

in figure 13.

VD = Voltage Drop

L = One way Length of

wire run

I = Current (in amperes)

used by our equipment

R = DC Resistance per

1,000’ of wire used per

gauge size

Size (awg) Ohms/1000' @ 250C

28 66.2

26 41.6

24 26.2

22 16.5

20 10.4

18 6.51

16 4.09

14 2.58

12 1.62

1,000

Figure 1

: Voltage Drop Formula

Resistance Table

1 2 ... 26 27 28 29 30 31 32 33 34 35 36 ... 113 114

Sem comentários

WaveWare Apollo T-2000 Informações Técnicas Página 31