Morningstar SunSaver 20 Amp 12 Volt PWM Charge Controller

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Manufacturer Part Number: SS-20L-12V

Morningstar's SunSaver (SS-20L-12V) is the world's leading small solar controller for both professional and consumer applications including standard features and capabilities not found in any other small PV controller.

SunSaver’s technology provides:

• Exceptional Reliability
• PWM Battery Charging
• Consistent High Quality

The SunSaver's advanced design delivers outstanding performance and value. The SunSaver’s low cost is made possible by Morningstar’s unique approach to design and manufacturing:

• Automated production
• ISO 9002 quality programs
• Latest power electronic technologies
• Latest control and logic technologies
• High volume manufacturing

It is a fully epoxy encapsulated outdoor rated 10 Amp "ice cube" sized 12V PWM charge controller. It has built-in temperature compensation, lightning protection and easy 4-wire hookup. The SunSavers's regulation voltage is set at 14.1 (best for sealed or gel batteries) and is not adjustable for battery type like MorningStar's other controllers. It's dimensions are 6.0" x 2.2" x 1.3" and it weighs just 8 oz.

Features:

• Seven versions available
• 100% solid state
• Series design (not shunt)
• True 0 to 100% PWM duty cycle
• Setpoint accuracy to 35 mV
• Rated for 25% overloads
• Fully encapsulated in epoxy potting
• Marine rated terminals/anodized case
• Temperature compensation
• Sealed/Flooded battery select
• No need to derate
• Parallel for 40 amps or more
• Green charging/Red LVD indicators
• Approved for use in hazardous locations – Class 1, Division 2, Groups A, B, C, D

Specifications

Electrical

Mechanical

• Wire size: #10 AWG (5.2 mm2)
• Anodized aluminum case
• Marine rated terminals
• Epoxy encapsulated
• Weight is 8 oz (0.23 kg)

Comparison

Detailed Description

The SunSaver is rated for 12 volt (or 24 volt) PV systems. Do not connect to a PV array with open circuit voltage (Voc) greater than 25 (or 44) volts.

• Maximum array short circuit current rating:

  SUNSAVER-6	8.1 amps
  SUNSAVER-10	12.5 amps
  SUNSAVER-20	25.0 amps

• Because the SunSaver is a series controller, the PV current rating is specified at the PV array’s peak power (Ipp). The SunSaver does NOT short the PV array for regulation, and it is not necessary to derate the controller for short-circuit current (Isc) as is commonly done with shunt controllers.
• SunSaver models with an automatic low voltage load disconnect function (LVD) are rated for either 6, 10 or 20 amp loads depending on the model.
• SunSaver models without an LVD capability are rated for a maximum load of 10 amps. All loads connected to the SunSaver LOAD terminals should not exceed 10 amps of current.*
• The rated PV input current and the rated load current can both be exceeded by 25% for up to 5 minutes. This 25% overload will reduce the safety margins for surges and will cause heating that can shorten the life of the controller. For the reasons noted above, these higher overload ratings should NOT be used for routine operation. They are only to note overload capability for system design purposes.
• The SunSaver is designed to operate continuously in 60°C ambient temperatures. However, do not install the controller near heat generating sources or in direct sun. This could cause the temperature rating to be exceeded and damage the controller.
• The date of manufacture can be found on the serial number (bottom of case). The first 4 digits are the year and week.

* It is not necessary to use the SunSaver load terminals. Loads that exceed the load rating of the SunSaver can be connected directly to the battery.

Functions

• 100% Solid State

  All power switching is done with FETs. No mechanical relays are used in the controller.

• Battery Charge Regulation

  SunSaver uses an advanced series PWM charge control for constant voltage battery charging. A true 0 to 100% PWM duty cycle is very fast and stable for positive charge control under all system conditions.

• Temperature Compensation

  A sensor next to the green LED measures ambient temperature conditions. The SunSaver corrects the constant voltage setpoint –28 (–56 for 24V) mV per °C with a 25°C reference. This correction matches the battery charging to the changing electrochemical properties of the battery, and works best if the battery and controller are in a similar thermal environment.

• Sealed / Flooded Select

  Flooded batteries require more vigorous charging to avoid stratification, and sealed batteries require precise control to avoid outgassing. The SunSaver constant voltage setpoints are 14.4 (or 28.8) volts for flooded batteries, and 14.1 (or 28.2) volts for sealed batteries. See Section 5.3-7 for more information.

• LED Indicators
• Low Voltage Disconnect (LVD)

  The automatic load disconnect is an option. If the battery falls below 11.5 (or 23.0) volts, the load is disconnected from the battery to protect against harmful deep discharges. A 2-second delay prevents load disconnects from transients. The load is automatically reconnected when the battery voltage recovers to 12.6 (or 25.2) volts.

• Battery Disconnect

  If the battery is disconnected during the daytime, the PV array will continue to provide power to the controller. The SunSaver will immediately go into PWM and provide power at a constant voltage to the load. This may continue as long as power is available from the PV array.

• Parallel Controllers

  The SunSaver controllers work very well in parallel configurations. No blocking diodes are required. The only constraint is that each controller must have an independent and separate PV subarray and load. Make sure that each SunSaver’s rating for PV and load current is not exceeded.

• Auxiliary Generators

  Engine generators and other sources of power may be connected directly to the battery for charging. It is not necessary to disconnect the SunSaver from the battery. However, do not use the SunSaver to regulate these other generators.

• Reverse Current

  The SunSaver prevents the battery from discharging through the PV array at night. There is no need to install a blocking diode for this purpose.

• Noise

  The SunSaver circuit minimizes switching noise and filters all noise output to extremely low levels when the system is properly grounded. If noise is present in a telecom load, it is most likely a grounding problem in the system.

Notes

• The SunSaver prevents reverse current leakage at night, so a blocking diode is not required in the system.
• The connector terminals will accept a maximum wire size of AWG #10 (up to 5.2 mm2).
• The SunSaver is designed to regulate power from a PV array. Other generators can be connected directly to the battery, however, with no effect on the SunSaver.
battery, however, with no effect on the SunSaver.

Warranty: Five year warranty period. Contact Morningstar for complete terms.