Go Power GP-MPPT-85/20 User manual

GP-MPPT-85/20
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© 2019 GoPower!
User Manual
GP-MPPT-85/20

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Contents
1.0 Installation Overview.............................................................................. 3
1.1 Introduction 3
1.2 Regulatory Information 3
1.3Specifications 3
2.0 IMPORTANT SAFETY INSTRUCTIONS ....................................................... 5
3.0 Choosing a Location................................................................................ 6
4.0 Choosing an Array................................................................................... 6
5.0 Installation.............................................................................................. 7
5.1 Tools and Materials Needed 7
5.2 Instructions 7
6.0 Wiring Diagram....................................................................................... 8
7.0 Operating Instructions............................................................................ 9
7.1 Battery Charging Profile Chart 9
7.2 LED Display 9
7.3 Switching Between Battery Banks 10
8.0 Frequently Asked Questions (FAQs)...................................................... 10
9.0 Troubleshooting Problems.................................................................... 10
9.1 Blank LED Display 11
9.2 Red Battery LED On 11
9.3 Red Solar LED On 12
9.4 Problems with Charging 12
10.0 Limited Warranty.................................................................................. 14
10.1 Repair and Return Information 14

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1.0 Installation Overview
1.1 Introduction
A Solar Controller (or Charge Controller / Regulator) is an essential component
of your photovoltaic solar system. The Controller maintains the life of the battery
by protecting it from overcharging. When your batteries have reached a 100%
state of charge, the Controller prevents overcharging by limiting the current
flowing into the batteries from your solar array.
The GP-MPPT-85/20 is a photovoltaic (PV) charge controller intended for use at
12 or 24 VDC system voltage and is rated for a nominal charge current of 20
amps.
The GP-MPPT-85/20 uses Maximum Power Point Tracking (MPPT) technology
and a unique three stage charging algorithm.
The GP-MPPT-85/20 is suitable for use with lead acid batteries.
1.2 Regulatory Information
1.3 Specifications
Values before and after the slash correspond to 12 and 24V
systems respectively.
Description
Value
Dimensions (H x W x D):
150 x 128 x 42 mm
5.90 x 5.03 x 1.65 in
Weight: 1050 g
37.03 oz
Warranty: 5 years
•MPPT charging
•3 stage charging
•LED display for errors
and charging state
•Reverse polarity
protected
Nominal System Voltage
12 / 24 VDC (auto detection)
Nominal Charge Current
20 ADC
Battery Input Voltage
Range
9.0 to 15.5 VDC in 12V systems
18.0 to 31.0 VDC in 24V systems
Max. Solar Array Current
Input
25 ADC
Refer to Section 4.0
Max. Solar Array Power
Input
250/500 W
Max. Solar Voltage Input
85 VDC
Must include temperature effects.
Refer to section 4.0

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Min Solar Voltage for
Charging
17.0/34.0 VDC
•Temperature
compensated
•RoHS compliant,
environmentally safe
•Accepts up to 250
watts of solar at 12
volts, up to 500 watts
of solar at 24 volts
Max. Series Fuse or Circuit
Breaker Rating for Battery
30 ADC
Grounding
Negative ground
Operating Consumption
7-15mA
Battery Types Supported
Lead acid
Battery Voltage Charge
Range
9.0 to 14.8 VDC in 12V systems
18.0 to 29.6 VDC in 24V systems
Bulk/Absorption Voltage
(AGM)
14.4/28.8V (25°C, 77°F),
30min per day
or 2hr if battery voltage < 12.3/24.6V
Float Voltage
13.8/27.6V (25°C, 77°F)
Battery overvoltage
protection level
15.5/31.0 VDC
Temperature Compensation
-25 mV/K in 12V systems
-50mV/K in 24V systems
Operating Temperature
- 40 to 60°C, - 40 to 140°F
Humidity
99% N.C.
Wire Leads
13 AWG
Connectors
Solar +: Male MC4 type
Solar -: Female MC4 type
Battery: Delphi Weather Pack 2
position male shroud
Protection
Battery Reverse Polarity,
Solar Array Reverse Polarity, Over
Temperature, PV Short Circuit,
Battery Short Circuit, Over Current
The total rated maximum open circuit voltage of the PV input should not exceed 85 volts.
GP-MPPT-85/20 will not allow charging when connected to greater than 85 volts of PV input
and will be permanently damaged by 100V or more of PV input. Be sure to account for
temperature effects. Consult section 4.0 for sizing guidelines.
The total rated maximum current of the PV input should not exceed 20 amps.
The GP-MPPT-85/20 will limit solar current above 20 Amps, and excess current will not be
utilized. Consult section 4.0 for sizing guidelines.
Overcurrent protection is required between the controller and battery.

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2.0 IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
THIS MANUAL CONTAINS IMPORTANT INSTRUCTIONS FOR MODEL GP-
MPPT-85/20 THAT SHOULD BE FOLLOWED DURING INSTALLATION AND
MAINTENANCE OF THE CHARGE CONTROLLER.
Disconnect all
power sources
Electricity can be very dangerous. Installation and
maintenance should be performed only by a
licensed electrician or qualified personnel.
Battery and
wiring safety
Observe all safety precautions of the battery
manufacturer when handling or working around
batteries. When charging, batteries produce
hydrogen gas, which is highly explosive. All
conductors attached to a battery must have
appropriate fuses or circuit breakers.
Wiring
connections
Ensure all connections are tight and secure. Loose
connections may generate sparks and heat. Be
sure to check connections one week after
installation to ensure they are still tight.
Work safely
Wear protective eyewear and appropriate clothing
during installation. Use extreme caution when
working with electricity and when handling and
working around batteries.
Observe
correct polarity
The controller will not function unless battery wire
leads are connected to a battery with correct
polarity. If the PV array is connected with reverse
polarity, it will cause a short circuit. Failure to
correct these faults could damage the controller.
Do not exceed
GP-MPPT-85/20
max current
ratings
Add parallel-connected PV module rated short
circuit currents (Isc) at STC. The resulting current is
not to exceed 20A. If your solar system exceeds
this value, contact your dealer for an alternate solar
array configuration or suitable controller alternative.
Refer to section 4.0.
Do not exceed
GP-MPPT-85/20
max voltage
ratings
The voltage rating of the solar array is the sum of
the Open Circuit Voltages (Voc) at STC of the PV
panels in series, multiplied by 1.25 (or by a value
from NEC 690.7 provided in Table 690.7 A). The
resulting array Voc voltage is not to exceed 85V. If
your solar array exceeds this rating, contact your
dealer for an alternate array configuration or
suitable controller alternative. PV voltage increases
in cold weather. Refer to section 4.0.

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3.0 Choosing a Location
The GP-MPPT-85/20 is designed to be mounted vertically. Allow at least 2in
(5cm) of space around GP-MPPT-85/20 for cooling. Install on non-flammable
surface. Do not install in direct sunlight.
The GP-MPPT-85/20 should be:
•Mounted as close to the battery as possible
•Mounted on a vertical surface to optimize cooling of the unit
•In an area with ventilation to dissipate hydrogen gas from batteries as
well as heat from the controller
4.0 Choosing an Array
The panel voltage should not exceed 85V, or the controller will not charge the
batteries. Panel voltage increases in cold weather compared to nameplate
standard test condition (STC) ratings, so the highest panel array voltage must be
calculated for the worst-case cold weather.
1. Determine the worst-case cold temperature of the panel installation.
2. Select the NEC temperature correction factor matching the worst-case
cold temperature of the panel installation. Refer to table 690.7(A) of
NEC 2017 or the latest version. When in doubt, select 1.25.
3. Sum the open circuit voltages (Voc) of panels wired in series to obtain
the array open circuit voltage at standard test conditions (STC).
4. Multiply the array open circuit voltage by your selected NEC
temperature correction factor, or multiply by 1.25 if you don’t know
which factor to choose.
5. The calculated value must be less than 85V. If not, select a different
wiring configuration for the solar panels with fewer in series.
For example, the FLEX-100 has a Voc of 20.8V at STC. If four FLEX-100 solar
panels were wired in series, then the array Voc would be 83.2V at STC. If the
array were to be used in temperatures down to -40°C, then the NEC temperature
correction factor would be 1.25. Multiplying the array Voc by 1.25 is 104V. This is
greater than the allowed 85V, and the panels must be wired in a different
configuration.
NEC 690.8 defines maximum solar current as the sum of parallel connected PV
module short circuit currents (Isc) at STC multiplied by 1.25. This should not
exceed 25A. Equivalently, the sum of the short circuit currents before the NEC
factor is applied should not exceed the controller nominal current of 20A.

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5.0 Installation
5.1 Tools and Materials Needed
•Philips Screwdriver (for mounting screws)
If the GP-MPPT-85/20 Controller was purchased with a Go
Power! RV Solar Power Kit then UV resistant wire is included.
For instructions regarding the Go Power! RV Solar Power Kit
installation, please refer to the Installation Guide provided with the Kit.
5.2 Instructions
1. Complete the installation of the solar modules. If this GP-MPPT-
85/20 was purchased as part of a Go Power! Solar Power Kit, follow the
Installation Guide provided. Otherwise, follow manufacturer’s
instructions for solar module mounting and wiring. Keep the solar array
covered with an opaque material until all wiring is complete.
2. Attach temperature sensor ring terminal to battery. Attach ring
terminal to battery lug or use neoprene tape to attach ring terminal to
battery case.
3. Mount the GP-MPPT-85/20. Mount GP-MPPT-85/20 to a non-
flammable surface. Mount vertically for proper heat dissipation.
4. Select wire type and gauge. If this GP-MPPT-85/20 was purchased
as part of a Go Power! Solar Power Kit, appropriate wire type, gauge
and length is provided.
Wire type is recommended to be a stranded copper UV resistant wire. Wire
fatigue and the likelihood of a loose connection are greatly reduced in stranded
wire compared to solid wire. Wire gauge should be able to sustain rated current
and minimize voltage drop.
IMPORTANT: All wiring must be in accordance to National Electrical Code,
ANSI/NFPA 70.
IMPORTANT: Identify the polarity (positive and negative) on the cable used for
the battery and solar module. Use colored wires or mark the wire ends with tags.
Although the GP-MPPT-85/20 is protected, reverse polarity contact may damage
the unit.
5. Complete battery wiring. Wire an appropriate fuse or breaker to the
battery bank positive terminal. Wire the GP-MPPT-85/20 to the battery
bank according to the wiring schematic in Section 6.0. Connect
negative battery wire directly to the controller, not via the vehicle
chassis. With battery power attached, the controller should power up
and display LEDs.

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Use of a positive or negative distribution bus is allowed between the controller
and battery as long as it is properly sized, electrically safe and an adequate wire
size is maintained.
IMPORTANT: Always use appropriate circuit protection on any conductor
attached to a battery.
6. Complete solar wiring. Connect the solar wiring to the controller. Then
remove the opaque material from the solar array. Connect negative
solar array wire directly to the charge controller, not via the vehicle
chassis.
Congratulations, your GP-MPPT-85/20 should now be operational. If the battery
power is low and the solar array is producing power, your battery should begin to
charge.
WARNING: This unit is not provided with a GFDI device. This charge
controller must be used with an external GFDI device as required by
Article 690 of the National Electric Code for the installation location.
6.0 Wiring Diagram
WARNING: When the photovoltaic (solar) array is exposed to light, it
supplies a dc voltage to this equipment
The fuse or breaker used
should be no larger than
30A.

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7.0 Operating Instructions
7.1 Battery Charging Profile Chart
Values before and after the slash correspond to 12 and 24 V
systems respectively.
7.2 LED Display
Start Up
When GP-MPPT-85/20 is connected to the battery bank, the controller will start a
power up mode which takes several seconds to complete.
LED Indicators
LED Icon
and Color
LED Status
Indication
Green
On
Controller connected to battery, night or no PV
detected
Flash
Controller connected to battery, day detected
Off
Battery connected with reverse polarity or not
connected
Red
On
Charging failure (PV overvoltage or overcurrent)
Off
Normal charging status
Red
On
Very low battery voltage or battery overvoltage
Off
Battery voltage in normal range
The green LED may flash for a few minutes after startup even if no PV is
detected. This delay is to avoid erratic day/night transitions.
Battery Type
Lead Acid
Float Charge at 25°C:
13.8/27.6V (± 0.1/0.2V)
Bulk/Absorption Charge at 25°C:
Set to 30 minutes every morning. Applied for 2 hours
if the battery voltage drops below 12.3/24.6 volts.
14.4/28.8V (± 0.1/0.2V)
The term lead acid is a generic battery designation. Choose the charging profile that works best
with your battery manufacturer’s recommendations.

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7.3 Switching Between Battery Banks
In some applications, two battery banks with different nominal voltages need
charged from the same solar array. An external switch or relay can be used to
select which battery bank is charged by the controller.
GP-MPPT-85/20 automatically determines nominal system voltage at startup. If
there is a large jump in battery voltage (i.e. switching from one battery bank to
another with a different nominal voltage), then the controller will detect the new
nominal system voltage and reset.
WARNING: Switching must be done with an external device. Each
battery bank must have a fuse or breaker. The switching circuit must
not allow the battery banks to be connected/shorted.
8.0 Frequently Asked Questions (FAQs)
Before a problem is suspected with the system, read this section. There are
numerous events that may appear as problems but are in fact perfectly normal.
Please visit gpelectric.com for the most up-to-date
FAQs.
It seems like my flooded batteries are losing water over time.
Flooded batteries may need to have distilled water added periodically to replace
fluid loss during charging. Excessive water loss during a short period of time
indicates the possibility of overcharging or aging batteries.
When charging, my flooded batteries are emitting gas.
During charging, hydrogen gas is generated within the battery. The gas bubbles
stir the battery acid, allowing it to receive a fuller state of charge.
IMPORTANT: Ensure batteries are in a well-ventilated space.
9.0 Troubleshooting Problems
How to Read this Section
Troubleshooting Problems is split into four sub-sections, grouped by symptoms
involving key components. Components considered irrelevant in a diagnosis are
denoted ‘Not Applicable’ (N/A). A multimeter or voltmeter may be required for
some procedures listed.
Check the controller LED display as the first step.
It is imperative all electrical precautions stated in the Safety
Instructions and outlined in the Installation Section are followed.
Even if it appears the system is not functioning, it should be
treated as a fully functioning system generating live power.

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9.1 Blank LED Display
Display Reading: Blank (no LEDs)
Time of Day: Daytime/Nighttime
Possible Causes:
Battery voltage or connection, blown fuse/breaker, wiring/connector problems
How to tell:
1. Check the battery voltage. If battery voltage is <9V, the controller will
not charge, and the LEDs may not function correctly.
2. Check wiring polarity.
3. Check all fuses/breakers, wires, and connections. A blown fuse/breaker,
damaged wire, or loose connection will prevent battery power from
reaching the controller.
Remedy:
1. Use an external charging source to charge the battery voltage above
9V. Consider battery replacement.
2. Correct any reverse polarity connections.
3. Check that all connections are clean, tight, and secure. Check that all
wires and insulation are intact. Check for possible shorts or damaged
equipment. Replace blown fuses or reset breakers.
9.2 Red Battery LED On
Display Reading: Red battery LED on
Time of Day: Daytime/Nighttime
Possible Cause:
1. Battery voltage is too low because of excessive voltage drop from
battery bank to controller or insufficient solar power.
2. Battery voltage is too low because of excessive load power draw from
battery bank.
3. Battery voltage is too high because of secondary charging source.
4. Battery voltage is too high because of a short.
How to tell:
Check the battery bank voltage with a voltmeter. Less than 11.9/23.8V is a low
battery voltage. Above 15.5/31.0V is a high battery voltage.
Check the battery voltage when loads are on and recheck when loads are off. If
there is a voltage discrepancy of more than 1V, the loads may be too large.

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Remedy:
1. Check all wiring and connections from the controller to the battery bank.
Ensure that all connections are clean, tight, and secure. Shorten the
distance from the controller to battery bank or obtain larger wire. It is
also possible to double up the existing gauge wire (i.e. two wire runs) to
simulate a larger wire. Wait for system to charge battery. Turn off loads
for faster charging.
2. Increase the battery bank capacity. Consult your dealer or installer for
assistance.
3. Remove any secondary charging source. GP-MPPT-85/20 will only
begin charging after battery voltage has fallen to a normal level. Use a
voltmeter to check if voltages are in correct range.
4. De-energize system and disconnect equipment. Use a DMM with a
connectivity setting to check for shorts in wiring or equipment.
Otherwise, use a voltmeter to check if voltages are in correct range.
9.3 Red Solar LED On
Display Reading: Red solar LED on
Time of Day: Daytime/Nighttime
Possible Cause:
1. PV array voltage is greater than 85V.
2. PV array current is greater than 20A.
How to tell:
Measure PV array voltage. If it’s greater than 85V, the controller will not charge.
Check PV module nameplate for ratings.
Remedy:
Change PV array wiring configuration. Consult your dealer or installer for
assistance.
9.4 Problems with Charging
Problem: Controller doesn’t seem to be charging
Time of Day: Daytime, clear sunny skies
Possible Cause:
Current is being limited as per normal operation or poor connection between
solar array and controller.
How to tell:
The green LED will flash if controller is charging. The green LED is on
continuously if controller isn’t charging or if there’s insufficient solar voltage.
With the solar array in sunlight, check the voltage of the solar array terminals with
a voltmeter.

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Remedy:
Check all connections from the controller to the array including checking for
correct wire polarity. Check that all connections are clean, tight, and secure.
Wait 5 minutes and recheck charging status. A delay is present to prevent erratic
behavior.
Problem: Charge current is less than expected
Time of Day: Daytime, clear sunny skies
Possible Causes:
1. Current is being limited as per normal operation.
2. Incorrect series/parallel configuration and/or wiring connections and/or
wire gauge.
3. Dirty or shaded module or lack of sun.
4. Blown diode in solar module when two or more modules are connected
in parallel.
How to tell:
1. Check battery voltage. If battery has reached the target charge voltage,
then current is being limited per normal operation.
2. Check the heatsink temperature. Controller will limit charge current
when internal temperatures are too high.
3. Check that the modules and batteries are configured correctly. Check all
wiring connections.
4. Modules look dirty, overhead object is shading modules or it is an
overcast day in which a shadow cannot be cast.
Avoid any shading no matter how small. An object as small as a
broomstick held across the solar module may cause the power
output to be reduced. Overcast days may also cut the power
output of the module.
Remedy:
Reconnect in correct configuration. Tighten all connections. Check wire gauge
and length of wire run.
Clean modules, clear obstruction or wait for conditions to clear.
If the open circuit voltage of a module is lower than the manufacturer’s
specifications, the module may be faulty. Check for blown diodes in the solar
module junction box which may be shorting the power output of module.

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10.0 Limited Warranty
GoPower warrants the GP-MPPT-85/20 for a period of five (5) years from the
date of shipment from its factory. This warranty is valid against defects in
materials and workmanship for the five (5) year warranty period. It is not valid
against defects resulting from, but not limited to:
•Misuse and/or abuse, neglect, or accident
•Exceeding the unit’s design limits
•Improper installation, including, but not limited to, improper
environmental protection and improper hook-up
•Acts of God, including lightning, floods, earthquakes, fire, and high
winds
•Damage in handling, including damage encountered during shipment
This warranty shall be considered void if the warranted product is in any way
opened or altered. The warranty will be void if any eyelet, rivets, or other
fasteners used to seal the unit are removed or altered, or if the unit’s serial
number is in any way removed, altered, replaced, defaced, or rendered illegible.
10.1 Repair and Return Information
Visit www.gpelectric.com to read the “frequently asked questions” section of
our website to troubleshoot the problem. If trouble persists:
1. Call your Go Power!® Technical Support team (1-866-247-6527).
2. Return defective product to place of purchase.

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© 2019 GO POWER!® By Valterra Products, LLC
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