Cotek SK120 Series User manual

SK120,SK200,SK350 Series
Pure Sine Wave Inverter
User’s Manual

Table of contents
1. Important Safety Information.………………………………………………
1-1 General Safety Precautions……………………………………………
1-2 Precautions When Working with Batteries……….…………………..
2. Features………………………………………………………………………...
2-1 Electrical Performance…………………………………………………
2-2 Mechanical Drawing of Socket Type(Power Claw PP75)… …..….
2-3 Mechanical Drawing of Strip Wire Type……………….…………….
3. Instructions………………………………………………….…………………
3-1 Front Panel Operation..………………………………………………...
3-2 Rear Panel Operation..…………………………………………………
3-3 Protections Features……..…………………………………………….
3-4 Installation.………………………………………………….…………...
3-5 Making DC Wiring Connections……...………………………………..
3-6
A
C Safet
y
Groundin
g
…………………………………………………...
3-7 Inverter Operation………………………………………………………
4. Troubleshooting guide………………………………………………………
5. Maintenance……………………………………………………………………
6. Warranty………………………………………………………………………..
DCopyright ：This manual is the copyright of COTEK Electronic lnd. Co., Ltd. Be not allowed to reproduc or copy
without permission of the owner.

1. Important Safety Information
1-1. General Safety Precautions
1-1-1. Do not expose the Inverter to rain, snow, spray, bilge or dust.
To reduce risk of hazard, do not cover or obstruct the ventilation
openings. Do not install the Inverter in a zero-clearance compartment.
Over heating may result.
1-1-2. To avoid a risk of fire and electronic shock. Make sure that existing
wiring is in good electrical condition; and that wire size is not
undersized.
Do not operate the Inverter with damaged or substandard Wiring.
1-1-3. This equipment contains components which can produce arcs or
sparks. To prevent fire or explosion do not install in compartments
containing batteries or Flammable materials or in locations which
require ignition protected equipment. This includes any space
containing gasoline-powered machinery, fuel tanks, or joints, fittings,
or other connection between components of the fuel system.
1-2. Precautions When Working with Batteries
1-2-1. If battery acid contacts skin or clothing, wash immediately with soap
and water. If acid enters eye, immediately flood eye with running
cold water for at least 20 minutes and get medical attention
immediately.
1-2-2. Never smoke or allow a spark or flame in vicinity of battery or engine.
1-2-3. Do not drop a metal tool on the battery. The resulting spark or
short-circuit on the battery of other electrical part may cause an
explosion.
1-2-4. Remove personal metal items such as rings, bracelets, necklaces,
and watches when working with a lead-acid battery,
A lead-acid battery produces a short-circuit current high enough to
weld a ring or the like to metal, causing a severe burn.
WARNING!
Before installing and using the Inverter, you need to read
the following safety information carefully.

2. Features
Pure sine wave output (THD < 3%)
Output frequency：50 / 60Hz switch selections
Input & output completely isolated design
High efficiency 84~94%
Capable of driving inductive & capacitive loads at the start moment.
A LED Indicator with twin color displays all operation status.
Loading and temperature controlled cooling fan.
Built in advanced microprocessor to make friendly interface with user.
Protection：Input low voltage Overload Short circuit
Low battery alarm Input over voltage Over temperature

2-1. Electrical Performance
Specification Model No.
Item SK120-112 SK120-124 SK120-148 SK120-212 SK120-224 SK120-248
Continuous Output Power 120W
Maximum Output Power 132W
Surge Rating (Max) 240W
Input voltage 12Vdc 24Vdc 48Vdc 12Vdc 24Vdc 48Vdc
Output Voltage 100 / 110 / 120Vac +/- 5% 220 / 230 / 240Vac +/- 3%
Frequency
(Switch Selections) 50 / 60Hz +/- 0.05%
Output Waveform Pure Sine Wave ( THD < 3% )
Efficiency (full load) Max *1 89% 91% 93% 92% 93% 94%
Input Voltage Regulation 10.5-15
VDC 21.0-30 VDC 42-60 VDC 10.5-15 VDC 21.0-30 VDC 42-60 VDC
Failure Indicator Red LED
Protection
Overload (Shut down),
Short Circuit (Shut down),
Reverse Polarity (Fuse),
Over / Under Input Voltage (Auto recovery),
Over Temperature (Auto recovery).
Remote Control Yes (ON / OFF mode controlled by hard wire) See 3-2
Safety Meet UL458 EN60950-1
EMC FCC Class A
EN55022:1997
EN61000-3-2:1998
EN61000-3-3:1995
EN55024:2001
e-mark
e13 023495
Operating Temperature Range 0 - 40 ℃
Storage Temperature Range -30℃to 70℃
Cooling convection cooling
Dimensions 185(L)x147(W)x60(H)mm / 7.3(L)x5.8(W)x2.36(H) Inch
Weight 1kg
Note: The specifications are subject to change without notice.
*1 : This test condition is normal DC input (13.5V) and temperature 25℃.

Specification Model No.
Item SK200-112 SK200-124 SK200-148 SK200-212 SK200-224 SK200-248
Continuous Output Power 200W
Maximum Output Power 220W
Surge Rating (Max) 400W
Input voltage 12Vdc 24Vdc 48Vdc 12Vdc 24Vdc 48Vdc
Output Voltage 100 / 110 / 120Vac +/- 5% 220 / 230 / 240Vac +/- 3%
Frequency
(Switch Selections) 50 / 60Hz +/- 0.05%
Output Waveform Pure Sine Wave ( THD < 3% )
Efficiency (full load) Max *1 87% 90% 92% 90% 93% 94%
Input Voltage Regulation 10.5-15
VDC 21.0-30 VDC 42-60 VDC 10.5-15 VDC 21.0-30 VDC 42-60 VDC
Failure Indicator Red LED
Protection
Overload (Shut down),
Short Circuit (Shut down),
Reverse Polarity (Fuse),
Over / Under Input Voltage (Auto recovery),
Over Temperature (Auto recovery).
Remote Control Yes (ON / OFF mode controlled by hard wire) See 3-2
Safety Meet UL458 EN60950-1
EMC FCC Class A
EN55022:1997
EN61000-3-2:1998
EN61000-3-3:1995
EN55024:2001
e-mark
e13 023496
Operating Temperature Range 0 - 40 ℃
Storage Temperature Range -30℃to 70℃
Cooling FAN (Controlled by load and temperature)
Dimensions 185 (L) x 147 (W) x 60 (H) mm / 7.3 (L) x 5.8 (W) x 2.36 (H) Inch
Weight 1.2kg
Note: The specifications are subject to change without notice.
*1 : This test condition is normal DC input (13.5V) and temperature 25℃.

Specification Model No.
Item SK350-112 SK350-124 SK350-148 SK350-212 SK350-224 SK350-248
Continuous Output Power 350W
Maximum Output Power 385W
Surge Rating (Max) 700W
Input voltage 12Vdc 24Vdc 48Vdc 12Vdc 24Vdc 48Vdc
Output Voltage 100 / 110 / 120Vac +/- 5% 220 / 230 / 240Vac +/- 3%
Frequency
(Switch Selections) 50 / 60Hz +/- 0.05%
Output Waveform Pure Sine Wave ( THD < 3% )
Efficiency (full load) Max *1 84% 86% 88% 86% 89% 90%
Input Voltage Regulation 10.5-15
VDC 21.0-30 VDC 42-60 VDC 10.5-15 VDC 21.0-30 VDC 42-60 VDC
Failure Indicator Red LED
Protection
Overload (Shut down),
Short Circuit (Shut down),
Reverse Polarity (Fuse),
Over / Under Input Voltage (Auto recovery),
Over Temperature (Auto recovery).
Remote Control Yes (ON / OFF mode controlled by hard wire) See 3-2
Safety Meet UL458 EN60950-1
EMC FCC Class A
EN55022:1997
EN61000-3-2:1998
EN61000-3-3:1995
EN55024:2001
e-mark
e13 023497
Operating Temperature Range 0 - 40 ℃
Storage Temperature Range -30℃to 70℃
Cooling FAN (Controlled by load and temperature)
Dimensions 185(L)x147(W)x60(H)mm / 7.3(L)x5.8(W)x2.36(H) Inch
Weight 1.4kg
Note: The specifications are subject to change without notice.
*1 : This test condition is normal DC input (13.5V) and temperature 25℃.

2-2. Mechanical Drawing of Socket (Power Claw PP75)
REMOTE PORT
ENB
CHASSIS
GROUND
ON
OFF
REMO.
POWER
ENB
GND
POS(+) NEG (-)
DC INPUT
Pure Sine Wave Inverter
PURE SINE WAVE INVERTER
60Hz
FREQ. 50Hz
POWER
STATUS
AC OUTPUT

2-3. Mechanical Drawing of Strip Wire Type
REMOTE PORT
OFF
ON POWER
GND
ENB
ENB
DC INPUT
REMO.
CHASSIS
GROUND
Pure Sine Wave Inverter
PURE SINE
WAVE
INVERTER
POWER
STATUS
60Hz
FREQ.
AC OUTPUT
50Hz

3. Instructions
This power inverter series is a the member of the most advanced line of mobile
AC power systems available.
To get the most out of the power inverter, it must be installed and used properly.
Please read the instructions in this manual before installation and operation this
model.
3-1. Front Panel Operation：
3-1-1. Front view：
POWER
STATUS
50Hz
FREQ. 60Hz
AC OUTPUT
PURE SINE WAVE INVERTER
PURE SINE
WAVE
INVERTER
AC OUTPUT
60Hz
50Hz
FREQ.
POWER
STATUS
3-1-2. AC Frequency：Selected by Dip Switch
Frequency Dip Switch
50 HZ ON
60 HZ OFF

3-1-3. Status：Display Power & Fault Status
Green LED LED Signal Status
Solid Power OK
Red LED LED Signal Status
Blink (Fast) OVP
Blink (Slow) UVP
Blink (Intermittently) OTP
Solid OLP
3-1-4. AC Output (available Sockets)：
3-1-5. DC Input (available type)：
PP75
CIGARET STRIPPED WIRE

3-2. Rear Panel Operation：
REMOTE PORT
GND
ENB
ENB
DC INPUT
POWER
REMO.
OFF
ON
NEG (-)
CHASSIS
GROUND
POS(+)
REMOTE PORT
CHASSIS
GROUND
REMO.
DC INPUT
ENB ENB
GND
POWER
ON
OFF
3-2-1. ON / OFF / REMOTE Main Switch.
3-2-1-1. Before installing the inverter, make sure the main switch must
be “OFF”.
3-2-1-2. Before using the remote unit, make sure the main switch must
be “ REMOTE”.
3-2-1-3. Ensure the remote control contact is off.
3-2-1-4. Remote Port：Place 0.75mm2and Screw type cable between
the remote port and the panel.
3-2-1-5. Remote port ON/OFF inverter setup status
VCEO > VBAT
MODE Ⅱ
MODE Ⅰ

NOTE: Only one of control mode can be presented. When operating.
3-2-2. DC Input Terminals：
Connect to 12V / 24V / 48V battery or the other power sources.
【＋】is positive,【－】is negative. Reverse polarity connection
will blow internal fuse and may damage inverter permanently.
DC Input Voltage
Model Minimum Maximum
12 V 10.5 15.0
24 V 21.0 30.0
48 V 42.0 60.0
3-2-3. Chassis Ground: using # 8 AWG wire to connect vehicle chassis.
MODE Ⅲ
MODE Ⅳ
WARNING!
Operation of the inverter without a proper ground
connection may result in an electrical safety hazard.

3-3. Protections Features:
DC Input (VDC) Over Temperature Protection
Over Voltage Under
Voltage INTERIOR
Model
Shut-
down Restart
Under
Voltage
Alarm Shut-
down Restart Shut-down Restart
12 V 16V 13V 11.0V <10.5V 12.5
24 V 32V 26V 22.0V <21.0V 25.0
48V 62V 52V 44.0V <42.0V 50.0
55℃45℃
Note: The specifications are subject to change without notice.
3-4. Installation：
Where to install. The power inverter should be installed in a location that
Meets the following requirements：
3-4-1. Dry – Do not allow water to drip or splash on the inverter.
3-4-2. Cool – Ambient air temperature should be between 0℃and 40℃, the
cooler the better.
3-4-3. Safe – Do not install in a battery compartment or other areas where
flammable fumes may exist, such as fuel storage areas or engine
compartments.
3-4-4. Ventilated – Allow at least one inch of clearance around the inverter
for air flow. Ensure the ventilation openings on the rear and front
of the unit are not obstructed.
3-4-5. Dust – Do not install the Inverter in a dusty environments
where are dust, wood particles or other filings/shavings are present.
These dust can be pulled into the unit when the cooling fan is
operating.

3-4-6. Close to batteries – Avoid excessive cable lengths but do not install
the Inverter in the same compartment as batteries.
Use the recommended wire lengths and sizes (see section 3-5).
Also do not mount the Inverter where it will be exposed to the
gases produced by the battery.
These gases are very corrosive and prolonged exposure also will
damage the Inverter.
3-5. Making DC Wiring Connections：
Follow this procedure to connect the battery cables to the DC input terminals
of the Inverter. Your cables should be as short as possible (Ideally,
less than 6 feet / 1.8 meters ) enough to handle the required current in
accordance with the electrical codes or regulations application. Cables are
not an adequate gauge (too narrow) or too long will decrease the inverter
performances such as poor surge capability and low input voltage warnings
frequently and shutdowns. UVP warning presents due to DC voltage drop
across the cables from the inverter to the batteries.
The longer or narrower the cables, the greater the voltage drop.
Increasing your DC cable size will help improve the situation.
Following cable recommendations for the best performance of inverter.
(Apply both 120V and 230V versions )
WARNING!
The installation of a fuse must be on positive cable.
Failure to place a fuse on “+” cables running between
the inverter and battery may cause damage to the
inverter and will void warranty.
WARNING!
Shock Hazard. Before proceeding further, carefully
check that the Inverter is NOT connected to any
batteries, and that all wiring is disconnected from any
electrical sources. Do not connect the output terminals
of the Inverter to an incoming AC source.

3-6. AC Safety Grounding：
The AC output ground wire should go to the grounding point for your loads
( for example, a distribution panel ground bus ).
3-6-1. Neutral Grounding (GFCI’S)：
3-6-1-1. 120V models：The neutral conductor of the AC output circuit
of the Inverter is automatically connected to the safety
ground during inverter operation. In accordance with the
National Electrical Code requirements that separately derived
AC sources (such as inverter and generators) have their
neutral conductors tied to ground in the same way that the
neutral conductor from the utility is tied to ground at the AC
breaker panel. For models configured with a transfer relay,
while AC utility power is presenting and the Inverter is in
bypass mode, this connection (neutral of the Inverter’s AC
output to input safety ground) is not present so that the utility
neutral is only connected to ground at your breaker panel,
as required.
3-6-1-2. 230V models：There is no connection made inverter interior
between either the line or neutral conductor to the safety
ground.
WARNING!
Risk of electronic shock. Use only Pass and Seymour, type
2095-W or 7899-W, ground – fault circuit-interrupter
receptacles. Others may fail in operating the inverter when
connecting to the inverter’s equipment.

Ground Fault Circuit Interrupters (GFCI)：
Installations in Recreational Vehicles (for North American approvals) will
require GFCI protection of all branch circuit connected to the AC output of
the hardwire terminal equipped Inverter. In addition, electrical codes
require GFCI protection of certain receptacles in residential installations.
While the pure sine wave output of the Inverter is equivalent to the
waveform provided by utilities, compliance with UL standards requires us to
test and recommend specific GFCI.
Cotek has tested the following GFCI – protected 20A receptacles and found
that they functioned properly when connected to the output of the Inverter.
3-7. Inverter Operation：
To operate the power inverter, turn the main switch ON. The power inverter
is now ready to deliver AC power to your loads. If there is several loads use,
turn them on separately after the inverter has been “ON” in order to prevent
the OVP present caused by the surge power.
3-7-1. Set the power switch to the “ON” position and the buzzer will send
out “Beep” sounds at the moment the inverter will do self-diagnosis,
then the Power Status LED indicators will also appear various colors.
Finally the buzzer will sound another “Beep” and the Power Status
LED indicators will turn to “Green” color, the inverter starts working
successfully.
3-7-2. Set the power switch to the OFF position, the inverter stops and all
the lights that are On, go Off.
3-7-3. Set power inverter switch to the ON position and turn the test load
On. The inverter should supply power to the load. If you plan to
accurately measure the true output r.m.s. voltage of inverter, a meter
such ad FLUKE 45 BECKMAN 4410 or TRIPLETT 4200 must be
used.

4. Troubleshooting guide：
Problems and Symptoms Possible Cause Solutions
“No AC Power Output”
STATUS illuminates the red LED
a. Blinking fast Over input voltage.
( OVP ) Check input voltage. Reduce input voltage.
b. Blinking slow. Low input voltage.
( UVP ) Recharge battery. Check connections
and cable.
c. Blinking Intermittently. Thermal shutdown.
( OTP )
Improve ventilation.
Make sure ventilation
openings in inverter
are not obstructed.
Reduce ambient
temperature.
d. Solid ON. Short circuit or Wiring
error.
Overload.(OLP)
Check AC wiring for
short circuit.
Reduce load.
WARNING!
Do not open or disassemble the Inverter.
Attempting to service the unit yourself may result in a
risk of electrical shock or fire.

5. Maintenance：
Very little maintenance is required to keep your inverter operating properly.
You should clean the exterior of the unit periodically with a damp cloth to
prevent accumulation of dust and dirt.
At the same time, tighten the screws on the DC input terminals.
6. Warranty：
We warrant this product against defects in materials and workmanship for a
period of 24 months from the date of purchase and will repair or replace any
defective Power Inverter when directly returned, postage paid, to us.
This warranty will be considered void if the unit has suffered any obvious
physical damage or alteration either internally or externally and does not
cover damage arising from improper use such as plugging.
The unit into an unsuitable power sources attempts to operate products with
excessive power consumption requirements, or use in unsuitable environments.
This is the only warranty that the company makes.
No other warranties express or imply including warranties of merchantability
and fitness for a particular purpose.
Repair and replacement are your sole remedies and the company shall not be
liable for damages, whether direct, incidental, special or consequential, even
though caused by negligence or other fault.