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Home > Charge Controller Support > PWM Solar Charge Controller Support > PWM-10-FM > GP-PWM Solar Controller 10-FM: Installation & Mounting
GP-PWM Solar Controller 10-FM: Installation & Mounting
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How to install and mount GP-PWM Solar Controller 10-FM


Tools and Materials Needed


• Flathead Screwdriver (for wire terminals)

• Phillips Screwdriver (for mounting screws)


NOTE: If the GP-PWM-10-FM Controller was purchased with a Go Power! Solar Power Kit, then UV resistant wire is included. For instructions regarding the Go Power! Solar Power Kit installation, please refer to the Installation Guide provided with the Kit.


Choosing a Location


The GP-PWM-10-FM is designed to be mounted flush against a wall, out of the way but easily visible.


The GP-PWM-10-FM should be:


• Mounted as close to the battery as possible

• Mounted on a vertical surface to optimize cooling of the unit

• Indoors, protected from the weather


In an RV, the most common controller location is above the refrigerator. The wire from the solar array most commonly enters the RV through the fridge vent on the roof or by using the Go Power! Cable Entry Plate (sold separately) that allows installers to run wires through any part of the roof. PV connections should connect directly to the controller. Positive and negative battery connections must connect directly from the controller to the batteries. 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.


Installation Instructions


1. Prepare for mounting.

Use the template below to mark the four mounting holes and the cutting line for flush mounting your controller.



2. Complete the installation of the solar modules.

If this GP-PWM-10-FM 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.


Do not exceed the GP-PWM10-FM Amp current and max voltage ratings

The maximum current of the solar system is the sum of parallel-connected PV module– rated short circuit Currents (Isc) multiplied by 1.25. The resulting system current is not to exceed 12.5A. If your solar system exceeds this value, contact your dealer for a suitable controller alternative.


Do not exceed the GP-PWM10-FM max voltage ratings

The maximum voltage of the array is the sum of the PV module–rated open-circuit voltage of the series connected modules multiplied by 1.25 (or by a value from NEC 690.7 provided in Table 690.7 A). The resulting voltage is not to exceed 35V. If your solar system exceeds this value, contact your dealer for a suitable controller alternative.


3. Select wire type and gauge.

If this GP-PWM-10-FM was purchased as part of a Go Power! Solar Power Kit, appropriate wire type, gauge, and length is provided. Please continue to the article GP-PWM Solar Controller 10-FM: Operations. If the GP-PWM-10-FM was purchased separately, follow the instructions included here.


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.


Wire Strip Length

Strip wires to a length of approximately 3/8 in (9 mm, as per strip gauge).


Suggested Minimum Wire Gauge

(Cable length 25 ft. max. from solar array to battery bank)


  • 80-Watt Solar Module #10 Wire Gauge
  • 100-Watt Solar Module #10 Wire Gauge
  • 160-Watt Solar Module #10 Wire Gauge
  • 170-Watt Solar Module #10 Wire Gauge
  • 190-Watt Solar Module #10 Wire Gauge


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-PWM-10-FM is protected, a reverse polarity contact may damage the unit.


Wiring the GP-PWM-10-FM

Wire the GP-PWM-10-FM according to the wiring schematic in Section 6. Run wires from the solar array and the batteries to the location of the GP-PWM-10-FM. Keep the solar array covered with an opaque material until all wiring is completed.


IMPORTANT: All wiring must be in accordance to National Electrical Code, ANSI/NFPA 70. Always use appropriate circuit protection on any conductor attached to a battery.


4. Connect the battery wiring to the controller first and then connect the battery wiring to the battery.


5. Torque all terminal screws per the following:

Stranded Copper 90°C Wire
Wire Size AWG Rated Torque (in-lbs)
14 20
12 20
10 20


With battery power attached, the controller should power up and display information. Connect the solar wiring to the controller and remove the opaque material from the solar array. The negative solar array and battery wiring must be connected directly to the controller for proper operation. Do not connect the negative solar array or negative battery controller wiring to the chassis of the vehicle.


6. Mounting the GP-PWM-10-FM.

Mount the GP-PWM-10-FM to the wall using the included four mounting screws.


IMPORTANT: You must set the battery type on the GP-PWM-10-FM before you begin to use the controller (follow steps in Section 7). The default battery setting is for AGM/LiFePO4 batteries.


Congratulations, your GP-PWM-10-FM should now be operational. If the battery power is low and the solar array is producing power, your battery should begin to charge.


7. Re-torque: After 30 days of operation, re-torque all terminal screws to ensure the wires are properly secured to the controller.


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.


Wiring Diagram


IMPORTANT: This diagram is valid only for version 1.5 and newer. Version 1.4 and older have different terminal locations.


The GP-PWM-10-FM Maximum 12.5A rating is based on a 10 amp total maximum short circuit current rating (Isc) from the parallel solar modules nameplate ratings. The National Electric Code specifies the PV equipment/system rating to be 125% of the maximum Isc from the PV module nameplate ratings (1.25 times 10 = 12.5A). Use the wiring diagram (below) to connect your battery to the battery terminals on the solar controller. First, connect the battery to the controller, and then connect the solar panel to the controller.


NOTE: The fuse or breaker used should be no larger than 15 amps.


NOTE: The controller will not work unless there is a battery connected to the battery terminals with at least 9V.


WARNING: When the photovoltaic (solar) array is exposed to light, it supplies a dc voltage to this equipment.



Products covered in this article: GP-PWM-10-FM

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