SamplexPower SAM Series, Owner'S Manual

Page: 18 / 40

18 | SAMLEX AMERICA INC.
specified by NEC Table 31.15 (B) (17). Further, NEC also specifies that wire size should be
based on Ampacity - 1.25 times the rated current flow.
resistance of wires and cables produces another undesirable effect of voltage drop.
Voltage drop is directly proportional to the resistance and the value of current flow.
Voltage drop produces loss of power in the form of heat. In addition, excessive voltage
drop from the battery to the Inverter may prematurely shut down the Inverter due to
activation of the Low Input Voltage Protection Circuitry of the inverter (10.5 ± 0.5V).
DC cables should be sized to ensure maximum voltage drop is limited to less than 5%.
4.6.5 effects of Low voltage on common electrical Loads:
Lighting circuits – incandescent and Quartz/Halogen: Loss in light output because
the bulb not only receives less power, but the cooler filament drops from white-hot
towards red-hot, emitting much less visible light.
Lighting circuits – fluorescent: Voltage drop causes an early proportional drop in
light output.
ac induction motors: These are commonly found in power tools, appliances, etc.
They exhibit very high surge demands when starting. Significant voltage drop in
these circuits may cause failure to start and possible motor damage.
4.6.6 requirement of fuse in Battery connection
A battery is a very large source of current. If there is a short circuit along the length
of the cables that connect the battery to the unit, thousands of Amperes of current
can flow from the battery to the point of shorting and that section of the cable will
overheat, the insulation will melt and is likely to cause fire. To prevent occurrence of
hazardous conditions under short circuit, fuse with Ampere rating ≥ 1.25 times the
maximum continuous current drawn by the inverter but ≤ the Ampacity of the connect
-
ing cable should be used for battery connection. The fuse should be fast acting Class-T
or Marine rated battery fuse Type Mrbf. rating of fuse is shown in Table 4.1 below. The
fuse should be installed as close to the battery Positive terminal as possible, preferably
within 7”. Please note that this fuse is required to protect the cable run from the battery
to the unit against short circuit. The unit has its own internal DC side fuses for internal
DC side protection.
4.6.7 making Dc Side connections
Recommended cable and fuse sizes for connecting battery are given in Table 4.1.
The maximum current for cable sizing / fuse rating has been considered at 1.25 times
rated continuous current draw at the rated output power.
table 4.1 recommended cable and fuse Sizes for Battery connection
rated Dc
input
current
1.25 times
rated current
for Sizing
cable Size
1
(ampacity)
max fuse
Size
2
Distance between
inverter, Battery and %
voltage Drop 3
Samlex fuse
(optional)
Samlex cable
+ fuse Kit
(optional) 3 ft. 6 ft. 10 ft.
150A 187.5A AWG#2
(215A)
200A 1.2% 2.3% 3.8% DC-FA-200 DC-2000-KIT
SeCTIOn 4 | Installation