CAVRO XP 3000, Руководство оператора, Страница: 16 / 134

Getting Started
1-10
6 x 1.5 = 9.0A; +4A = 13A (choose a 15A power supply)
In this example, it is assumed that all the pumps and other equipment will sometimes
operate simultaneously.
External equipment with inadequate bypass capacitance or that is inadequately sourced
for current can cause overvoltage transients and sags, and can create unnecessary ripple
current in the XP 3000. This can result in decreased component life. Additionally, it is
possible for a regulated power supply to become unstable with certain loads and oscillate
if adequate filter capacitance is not present. Some forms of oscillation can cause failures
in the XP 3000. These issues can be avoided by using a properly designed commercial
power supply.
Consideration should also be given to the wiring of the XP 3000 and any additional
devices. Wiring should be of sufficient gauge for the current, and as short as possible.
Unless otherwise required by safety requirements, the power supply lines to the XP 3000
should be 20AWG or heavier. Multiple XP 3000s can be daisy-chained, provided that the
wire size and the power supply are adequate for the total current. In the example of the
six XP 3000s above, use 18AWG wire if the units are daisy-chained. It is best if each pair
is twisted or dressed together from the device to the supply. For more information on
multi-pump cabling, see Chapter 2, “Hardware Setup.”
To control power to the XP 3000, switch power to the power supply. Do not use a relay
or switch contacts between the 24V supply and the XP 3000 (i.e., do not switch DC input
to the pump).
Switching Power Supplies
Be sure to check carefully the minimum load requirement of the power supply. Typically,
switching supplies have a minimum load requirement of up to 10% of the rated output
current.
NOTE The XP 3000 idle current is less than 10% of the full running current.
For example, in a system with multiple XP 3000s, a 24V 5-amp switcher with a
minimum load less that 500mA may not provide sufficient current when the XP 3000
motors are idle and all other devices are in a low current state. If the XP 3000 is the only
load on the 24V supply, a switcher should have a minimum load specification of 50mA
or less. An appropriate external power resistor can be used to ensure that the minimum
load is met.