SunGuard

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SunGuard

The SunGuard™ is a single module, compact PWM solar charge controller for small systems, ideal for both professional and consumer use. With SunGuard, there’s no reason not to insist on Morningstar quality with any system design—no matter how small.

“Rock solid, potted so waterproof, long
track-record…great charge controller for a small system”

Key features and benefits

  • Rugged design—100% solid state, epoxy encapsulated; rated for 25%
    overcurrents (no need to de-rate)
  • Longer battery life—series design PWM charging (instead of shunt)
    with temperature compensation, low self-consumption
  • Easy to install—outdoor rated connecting wires make a waterproof
    connection to the solar module and battery
A. Premium high-frequency CoilCraft surface mount inductors

They’re worth it, because they provide the faster power “tracking” that lets us engineer this much power and control into a compact design.

B. High-frequency design

Combined with premium, “over-spec’d” components, this greatly improves control response which guards against system transients, regulation overshoot and overcurrent/overload conditions

C. Built-in 4500W Transient Voltage Surge Suppression for lightning protection

Nature do your worst–this controller can take it

D. Large diameter, high torque, corrosion resistant terminals

If you’ve ever trashed a lesser terminal during an installation, you’ll appreciate some “overkill” here

E. DirectFET™ MOSFET power devices

Allows the surface-mounting of critical components underneath the main board next to the heat sink, which reduces heat travel distance and keeps the controller even cooler

F. Highly-conductive aluminum heatsink extrusion

As opposed to cast aluminum, which is less effective in passive cooling applications

G. Communications/data port with serial/meter auto detect

“Talks solar” with standard industry language, for system monitoring and cloud connectivity-speaks Modbus, and SNMP (with the EMC-1)

H. Lithium foldback circuit

Lithium batteries are expensive and vulnerable to cold temperatures. When it gets close to freezing, the controller backs-off charging to avoid damaging batteries

I. High-speed ARM processor

All-digital calibration for high accuracy, using the same efficient technology found in advanced mobile device

J. TrakStar™ Technology

Morningstar’s hallmark MPPT technology precisely seeks and locks onto the true maximum power point quickly and accurately, to ensure the highest output possible from a solar array

K. Large format, high-resolution backlit LCD

When you’ve been in the field installing, you appreciated being able to read a crisp, high contrast display on site

L. 5 year warranty

Up to 2 1/2 times longer than some competitors in this class

M. Self-diagnostics

ProStar is smart enough to monitor and analyze system performance, and alert you when you need to know

N. High temperature architecture

Heat is the enemy of all electronics. That’s why Prostar’s critical components are rated to withstand temperatures right up to the boiling point of water (100°C)

O. Lexan polycarbonate UL listed case

Protects the precision electronics inside with an impact strength 30 times greater than the acrylic thermoplastics commonly found on lesser controllers

P. Cooling Fan

Just kidding. We’ve never needed them

Specifications and Certifications

Model SG-4
*Input power can exceed Nominal Operating Power. Controller will limit and provide its rated continuous maximum output current into batteries.
Charge Rating 4.5 amps
Max. PV Open Circuit Voltage (Voc) 30 volts
Nominal Battery Voltage 12V
Self-Consumption 6mA
Voltage Accuracy 60mV
Operating Temperature Range -40 C to +60C
Warranty 5 Years
CE and RoHS compliant Yes
Manufactured in a Certified ISO 9001 Facility Yes

Videos

ProStar MPPT Controller - 4 minute video

This short video highlights the high quality of the ProStar MPPT solar charge controller, and its ability to regulate charging of lead acid, lithium, or nickel cadmium batteries in off-grid solar applications. The video also addresses lighting control, self-diagnostics, data logging, MODBUS communications, array oversizing, and low noise design.

Morningstar Charging Experts featuring ProStar MPPT

This 5 minute video highlights the ProStar MPPT solar charge controller’s circuit board that differentiates it from other brands. In addition to the capacitors, inductors, processors, surge protectors, and other over-spec’d internal components, the quality of the controller’s heat sink and outer casing is also addressed. The video concludes with mention of features and capabilities related to communications, datalogging, lithium battery charging, and high quality and reliability.  

New ProStar MPPT Solar Charge Controller

Recorded Webinar

This 30 minute recorded webinar gives a more in depth overview of how the ProStar MPPT solar charge controller fits into the existing Morningstar portfolio. The recording also includes answers to questions about operating temperatures, the display meter interface, and protections, faults and alerts.

Accessories

Sorry, we currently do not have any compatible products. Please check back soon.

Firmware

It’s a recommended best practice to install your product’s latest firmware to ensure access to all up-to-date features, accessory compatibilities, and code modifications. Watch this 5 minute video for instructions on how to download and update ProStar MPPT firmware.

After watching the video, click here to download the firmware.

System Diagrams

    Off-Grid Diagram with DC Load

The schematic diagram above, illustrates how the ProStar MPPT regulates power to batteries and a direct current (DC) load in an off-grid system.

  1. Sunlight contacts the solar modules, which convert solar into DC electrical power that it delivers to a charge controller.
  2. The charge controller regulates the amperage and voltage that is delivered to the loads and any excess power is delivered to the battery system so the batteries maintain their state of charge without getting overcharged.
  3. During the evening when there is no sunlight, battery power is used to run the load.

 


 

    Off-Grid Diagram with AC Load


The schematic diagram above, illustrates how the ProStar MPPT regulates power to batteries and an alternating current (AC) load in an off-grid system.  This diagram is very similar to the DC load diagram above it except an inverter has been added.

  1. Sunlight contacts the solar modules, which convert solar into DC electrical power that it delivers to a charge controller.
  2. The charge controller regulates the amperage and voltage that is delivered to the battery system so the batteries maintain their state of charge without getting overcharged.
  3. Batteries deliver power to the inverter which converts DC to AC power that it delivers to the load.  Notice that  the inverter is connected to the battery, not the controller’s load terminals, like we did in the DC load example.  That’s because the inverter can have a high energy surge upon start up, and this high current surge might be higher than the rated capacity of the charge controller, whereas the batteries will be able to meet the high energy surge requirement.