CPS SC Series User manual

CPS SC Series Grid-tied PV Inverter
CPS SC20KTL-DO/US-480
Installation and Operation Manual
Ver 1.2

Table of Contents
Before You Start… ......................................................................................1
Chapter 1 IMPORTANT SAFETY INSTRUCTIONS..................................2
Chapter 2 Overview..................................................................................5
2.1 Inverter for grid-tied PV systems...................................................5
2.2 Product type description................................................................5
2.3 Product features............................................................................5
2.4 Circuit structure design..................................................................6
2.5 Appearance description.................................................................7
Chapter 3 Installation...............................................................................8
3.1 Basic requirements........................................................................9
3.2 Mechanical installation..................................................................10
3.3 Electrical installation......................................................................18
3.3.1 DC connection.......................................................................18
3.3.2 AC and ground connection ....................................................23
3.3.3 Communication connection ...................................................26
Chapter 4 User Interface..........................................................................29
4.1 Description of LCD panel ..............................................................29
4.2 Operation state..............................................................................31
4.3 Interface and menu functions........................................................31
4.3.1 Interface types.......................................................................31
4.3.2 Menu functions......................................................................33
4.3.3 Operation information............................................................34
4.3.4 Alarm .....................................................................................35
4.3.5 History...................................................................................35
4.3.6 System setup.........................................................................36
4.3.7 Power Dispatch .....................................................................38
4.3.8 System protection parameters setup.....................................39
Chapter 5 Operation.................................................................................43
5.1 Start-up..........................................................................................43
5.2 Shut-down.....................................................................................43
5.3 Operation mode.............................................................................43
5.4 Grid connection and power generation..........................................45
5.5 Fault shutdown..............................................................................46
Chapter 6 Service and Maintenance.......................................................54
6.1 Disassembling of fan tray assembly..............................................54
6.2 Restoring of fan tray assembly......................................................56
Chapter 7 Technical Data.........................................................................60
Chapter 8 Limited Warranty.....................................................................62

1
Before You Start…
This manual contains important information regarding installation and safe
operation of this unit. Be sure to read this manual carefully before using.
Thank you for choosing this CPS Grid-tied PV Inverter. This PV Inverter is a
high performance and highly reliable product specifically designed for the
North American Solar market.
If you encounter any problems during installation or operation of this unit, first
check this manual before contacting your local dealer or supplier. Instructions
inside this manual will help you solve most installation and operation
difficulties.
Please keep this manual on hand for quick reference.

2
Chapter 1 IMPORTANT SAFETY INSTRUCTIONS
(SAVE THESE INSTRUCTIONS)
Please read this user manual carefully before product installation. CPS
reserves the right to refuse warranty claims for equipment damage if the user
fails to install the equipment according to the instructions in this manual.
Warnings and symbols in this document
DANGER:
DANGER indicates a hazardous situation which, if not avoided, will
result in death or serious injury.
WARNING:
WARNING indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
CAUTION:
CAUTION indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
NOTICE:
NOTICE indicates a hazardous situation which, if not avoided, could
result in equipment working abnormally or property loss.
INSTRUCTION:
INSTRUCTION indicates important supplementary information or
provides skills or tips that can be used to help you solve a problem or
save you time.

3
Markings on the product
HIGH VOLTAGE:
The product works with high voltages. All work on the product
must only be performed as described in this document.
HOT SURFACE:
The equipment is designed to meet international safety
standards, but surfaces can become hot during operation. Do not
touch the heat sink or peripheral surfaces during or shortly after
operation.
EARTH GROUND:
This symbol marks the location of grounding terminal, which
must be securely connected to the earth through the PE
(protective earthing) cable to ensure operational safety.
DANGER:
Please disconnect the inverter from AC grid and PV modules before
opening the equipment. When the PV array is exposed to light, it
supplies DC voltage to this equipment. Make sure hazardous high
voltage and energy inside the equipment has been discharged.
Do not operate or maintain the inverter until at least 10 minutes after
disconnecting all sources from DC and AC sides.
WARNING:
All the installation and wiring connections should be performed only
by qualified technical personnel. Disconnect the inverter from PV
modules and the Power Grid before maintaining and operating the
equipment.

4
CAUTION:
Although designed to meet international safety standards, the
PV-Inverter can become hot during operation. Do not touch the heat
sink or peripheral surfaces during or shortly after operation.
CAUTION:
CPS SC20KTL-DO/US-480 inverter is approx 132lbs (63kg).
Please ensure the mounting is properly installed before hanging the
the inverter on the bracket.
NOTICE:
This inverter is designed to connect AC power only to the public grid.
Do not connect the AC output of this equipment directly to any
private AC power equipment.
INSTRUCTION:
Conduits shall be used as the cable protectors for cable connection.

5
Chapter 2 Overview
2.1 Inverter for grid-tied PV systems
CPS SC20KTL-DO/US-480 inverter is suitable for use with commercial
and large scale PV grid-tied systems. The system is generally made up of PV
modules, DC power distribution equipment, PV inverter and AC power
distribution equipment (Figure 2-1). The inverter converts the DC from PV
modules to AC with the same frequency and phase as the AC grid. All or part
of the AC power is supplied to local loads, and the surplus power is supplied to
the electricity grid.
DC power
distribution
equipments AC Grid
Bidirectional
electric meter
AC power
distribution
equipments
Figure 2-1 Grid-tied PV system
2.2 Product type description
CPS SC20KTL-DO/US-480 is a two-MPPT PV inverter integrated with the
DC and AC switches for indoor and outdoor application. The suffix “US” means
that this model of inverter passes the UL certification and is specialized for the
American market.
2.3 Product features
CPS SC20KTL-DO/US-480 inverter incorporates the advanced 3-level
and MOSFET paralleled with IGBT technology to minimize the energy loss.
The two-MPPT design has the benefit of increasing the power generating

6
efficiency of the whole PV system. The inverter has 2 MPPTs, so a separate
array can be controlled by an independent Maximum Power Point Tracking
(MPPT) control circuit. This means that the two arrays can be installed in
different positions and orientations.
The transformerless design of inverter with the benefit of small size, light
weight and high power density, provides the best cost performance for the
whole PV system.
The inverter is available for both indoor and outdoor applications due to its
NEMA 3R (IP65) protection class enclosure.
The integrated DC and AC switches make the maintenance more flexible
and safer. Besides, the inverter has the function to support one or two
independent MPPTs input to improve the system efficiency. Meanwhile, the
inverter can automatically identify the connection way between PV modules
due to its excellent self-adaption ability.
2.4 Circuit structure design
The basic schematic diagram of CPS SC20KTL-DO/US-480 is shown in
Figure 2-2. The input DC passes through surge protection circuitry, DC EMI
filter, and the boost circuit to achieve maximum power tracking and boost up
voltages. The inverter converts the DC energy to 3-phase AC energy. The high
frequency components of AC voltage are removed with a line filter. Then the
3-phase AC energy is sent through two-stage relays and EMI filter to produce
high quality AC power.

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EMI
Filter
INV
EMI
Filter
L1
L2
L3
N
PE
Filter
Surge
Protector
DC_Switch
PV1+
PV1-
DC/DC
EMI
Filter
PV2+
PV2-
DC/DC
AC_Switch
Surge
Protector
Surge
Protector
Figure 2-2 Schematic diagram of CPS SC20KTL-DO/US-480
2.5 Appearance description
Figure 2-3 Appearance sketch of CPS SC20KTL-DO/US-480
Description of main items of the inverter (shown in Figure 2-3):
1. LCD key buttons: operate the functions and change settings of inverter
2. LCD display: indicates data
3. LED indicator lights: indicate the status of inverter
4. DC input knockouts (4), AC output & ground knockout (1) and signal port
(1) from left to right
5. DC switch: control the DC power on and off
6. AC switch: control the AC power on and off
7. Main housing
8. Wiring box

8
Chapter 3 Installation
Below is the installation instruction of the inverter. Please read carefully
and install the product step-by-step.
Before installation, please check that the following items are included in
the package:
Table 3-1 Main items
Item
Q’ty
Note
(1) CPS
SC20KTL-DO/US-480
Grid-tied PV inverter
1
Grid-tied PV inverter
(2) Mounting bracket
1
upon which Inverter is hung
and mounted onto a wall
(3) User manual
1
Installation and operation
manual
(4) Warranty card
1
for maintenance and repair
(5) Accessory kit
1
contains all necessary
accessories
The (5) Accessory kit contains items listed below:
Table 3-2 Accessories
Item
Q’ty
Purpose
M (8×25L) expansion
bolts & nuts
8 pairs
for bracket installation (2
pairs for backup use)
M5 nut
2
for grounding wire (1 nut for
backup use)
Ring terminal
1
for grounding wire
Cord end terminals
20
16 for input wires, 3 for

9
output wires, 1 for neutral
wire (optional)
RJ45 connecters
4
for communication cables
Red wire
1
for inverter with 1 MPPT
working alone
3.1 Basic requirements
Check that the product environmental specifications (protection degree,
operating temperature range, humidity and altitude, etc) meet the
requirements of the specific project location;
Make sure that the power grid voltage is within normal range;
Ensure that the local electricity supply authority has granted permission
to connect to the grid;
Installation personnel must be qualified electricians or people who have
received professional training;
Sufficient space is provided to allow the inverter cooling system to
operate normally;
Install the inverter away from flammable and explosive substances;
Avoid installing the inverter in locations that exceed the temperature
limits specified in the inverter data sheet to limit undesirable power loss;
Do not install the inverter near the electromagnetic source which can
compromise the normal operation of electronic equipment;

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3.2 Mechanical installation
(1) Dimensions
Figure 3-1 Dimensions of CPS SC20KTL-DO/US-480
(2) Installation method (see Figure 3-2):
Make sure that the mounting structure (wall, rack, etc) is suitable to
support the inverter weight. Follow the mounting guidelines below:
(a) If the location permits, install the inverter vertically.
(b) If the inverter cannot be mounted vertically, it is allowed to be tilted
backward by Max. 15°.
(c) Do NOT mount the inverter forwards.
(d) Do NOT mount the inverter in a horizontal position.
(e) Do NOT mount the inverter upside down.

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(a) (b)
(c) (d) (e)
Figure 3-2 Mounting the inverter properly
(3) Space required for inverter mounting on the wall (as shown in Figure
3-3)
The distances between the inverter and the surrounding objects should
meet the following conditions: two sides from the walls ≥11.81 inches; top
distance ≥11.81 inches; bottom distance ≥23.62 inches; the minimum spacing
between two adjacently mounted inverters ≥23.62 inches.

12
Figure 3-3 Inverter mounting dimensions
(3) Secure the bracket with bolts through the mounting holes and install
the inverter:
(a) Mark the 6 bolt holes for mounting the bracket as shown in Figure 3-4;

13
Figure 3-4 Bracket mounting dimensions
(b) Drill holes at the marked positions with a diameter of 0.4 inch drill
and put the 6 M8*25 expansion bolts into the holes;
(c) Take the mounting bracket out of the package and secure the
bracket on the wall with the 6 nuts in pair as shown in Figure 3-5;

14
Figure 3-5 Positions of bolt holes on the bracket
(d) Screw off the bolts and remove the two panels on both sides of the
inverter as shown in Figure 3-6;
Figure 3-6 Removal of panels before mounting inverter
(e) Two people grab at the position on each side, lift up the inverter
and then hang it on the bracket (Figure 3-7a~e). Make sure the
inverter is securely mounted on the bracket;

15
Figure 3-7a Mounting inverter on the bracket
Figure 3-7b Mounting inverter on the bracket
Hand Grab

16
Figure 3-7c Mounting inverter on the bracket
Figure 3-7d Mounting inverter on the bracket

17
Figure 3-7e Mounting inverter on the bracket
(f) Put the two removed panels back and secure them with 4 M4*12
bolts on each side, as shown in Figure 3-8.
Figure 3-8 Securing panels on both sides

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DC input
Signal port
AC output and ground
3.3 Electrical installation
The knockouts for cable entry of CPS SC20KTL-DO/US-480 are shown in
Figure 3-9:
Figure 3-9 Knockouts for cable entry
The 5 ports on the left are for DC input, AC output and ground
connections, matching the 1¼ & 1½ inch diagram of conduits; The last port on
the right is for communication, matching the ½ & ¾ inch diagram of conduits.
3.3.1 DC connection
(1) To ensure the optimal performance of the inverter, please read the
following guidelines before DC connection:
(a) First, make sure that the maximum open circuit voltage of the PV
modules is lower than 600Vdc under any conditions;
(b) The inverter has 2 MPPTs. Ensure that the Max. DC input current of
each MPPT does NOT exceed 35A.
(c) Confirm that the PV modules for each MPPT of the inverter are of the
same types and specifications before connection. The number,
INSTRUCTION:
Conduits shall be used as the cable protectors for cable connection.