Section II
General Product Information
006-0006885 08/14/18
Rev H
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MINV-4000-1U-28 Guide www.synqor.com
Power Cable Wiring Size
SynQor recommends the following cables for use with the MINV-4000 series:
AC Output: SYN-9630 MINV connection to hardwire termination, 10’
DC Input:
SYN-9651 MINV positive connection to hardwire termination, 10’
SYN-9652 MINV negative connection to hardwire termination, 10’
Other options may be available. Contact [email protected] or visit the website: http://www.
synqor.com for more information. If it is necessary to develop custom cables for your application,
please read through the following section for some important considerations. Damage caused
by improper wiring of cables will not be covered under SynQor’s warranty.
Both the input and output cables of the MINV carry substantial current, and since the wires in
these cables have resistance the current flowing through them causes a voltage drop from one
end of the cable to the other. In other words, the voltage across the cable at its downstream end
is smaller than the voltage across the cable at its upstream end. Mathematically, the amount
that the voltage drops is equal to the resistance of the cable’s wire multiplied by the current
flowing through the wire. It is therefore important to make sure that the resistance of the cable’s
wire is small enough to keep this voltage drop to an acceptably small value.
While this is an issue for all of the power cables, it is particularly important for the DC INPUT
cables because the current flowing through it is very high (as high as 240 A for the MINV-4000
Series) and the voltage across it is already relatively small (as low as 20 V). In fact, a common
problem that arises (when the DC INPUT cable has too small a wire) is that the voltage seen at
the DC INPUT of the MINV falls below the minimum specified value of 20 V even though the
voltage at the source of the DC power is greater than 20 V. Under this condition the MINV will
turn off its output even though the voltage at the DC source of power appears to be available
and at a proper level.
The resistance of a wire depends directly on its length. A wire twice as long as another will
have twice the resistance, holding all other things constant. The resistance also depends on
the reciprocal of the cross-sectional area of the wire, which in turn depends on the square of
the wire’s diameter. A wire with half the diameter of another will therefore have four times the
resistance, holding all other things constant.
Therefore, the longer a cable is, the more important it is that the wire’s diameter be large.
SynQor recommends that for the MINV-4000 Series:
• The AC OUTPUT cable has 3 wires (one for the ground) of ≥ 8 AWG for the 115 V output
model and ≥ 12 AWG for the 230 V output model
• The DC INPUT cable has 2 wires (one for each pole) of 0 (1/0) AWG
Additional details about the effects of a resistance-related voltage drop are included in “Trouble-
Shooting Guide - Cable wire resistance is too high”.
