Wybron NEXERA 2560, Manual, Page: 14 / 27

14
Head-Feet Restrictions
Head-Feet is defined as “the sum of cable lengths from each Nexera color module to a
single power supply output”. The Head-Feet parameter is a method of accounting for the
voltage drop in the power / signal cable caused by the current drawn by each color
module.
To help understand this issue, think of it as water pressure (voltage) in a hose (cable)
where you have multiple water sprinkler heads (Nexera color modules). If the hose
(cable) is too long or you have too many sprinkler heads (color modules), the water
pressure (voltage) will be too low.
Use the following equation to determine total head feet:
Head-Feet = [(A)+(A+B)+(A+B+C)+….]
where:
A = Cable length from power supply to first color module
B = Cable length between first and second color module
C = Cable length between second and third color module
and so on.
The maximum Head-Feet for each of the Nexera fixtures is as follows
Model 2560 Nexera Wash - Tungsten 1500 Head-Feet max.
Model 2570 Nexera Profile - Tungsten 1500 Head-Feet max.
Model 2580 Nexera Wash - CDM 1500 Head-Feet max.
Model 2600 Nexera Profile - CDM 1500 Head-Feet max.
Head-Feet Example
In the figure above four Nexera fixtures are daisy-chained off of the same power supply
output. Using the equation given above, total head-feet can be calculated as follows:
Head-Feet = [(A)+(A+B)+(A+B+C)+(A+B+C+D)]
= [(100) + (100 + 25) + (100 + 25 + 20) + (100 + 25 + 20 + 25)]
= [100 + 125 + 145 + 170]
= 540 Head-Feet
Since total Head-Feet (540) is less than the maximum (1500) this is a valid configuration.
A
100 feet
B
25 feet
C
20 feet
D
25 feet