Dry Contact Application of SPH-UP Model
With the increasing use of solar and storage systems, utilizing every piece of solar power adequately and properly is an important developing direction. When the solar and energy storage system becomes the core of the energy management center, it’s required to allocate the access of various home appliances, like water heaters and generators. Therefore, GROWATT develops the dry contact to meet such various applications
Wiring Connection of Dry Contact for Water Heater Application
GROWATT single-phase and three-phase SPH-UP model offer 12Vdc control voltage of the dry contact, coordinating with additional relay to realize the control of water heater, the power consumption of the relay control coil is required to be within 2W such as the Finder Type 48.12
Multiple Control Modes for Water Heaters
Export Power Control Mode
The export power control mode is based on the power feeding into the grid. When the power feeding into the grid is larger than the value of “D-Export Power”, the dry contact will offer a continuous 12Vdc power through the relay to activate the water heater. And the dry contact will stop offering the power when the feeding power is smaller than the value of “TurnOff P”. Additionally, you can add delay time and minimum running period to prevent the dry contact from acting frequently due to the power fluctuation
Export P: The dry contact will offer a continuous 12Vdc power when the power feeding into the grid is higher than it
OnDelay: The dry contact will act only when the feeding power is larger than the value of “Export P” for the set delay time
MinRun: The dry contact will continuously work at least for the minimum time, then it’s possible to stop.
TurnOff P: The dry contact will stop offering a 12Vdc power when the feeding power is lower than it.
Timer Control Mode
The dry contact will continuously offer a 12V power during the setting time.
Timer Control Mode
Combing the export power control mode and the timer control, the dry contact only acts when it meets the setting of the timer and the surplus feeding power
Wiring Connection of Dry Contact for Generator
There are two activation ways for the generator application including Low Battery SoC Activation and Manual Activation. The single-phase and three-phase SPH-UP model can offer a 12Vdc power of the dry contact to activate the generator, supplying the loads when the battery SOC is low without adequate power during the off-grid condition. Once the generator is on, its output cannot conflict with the output of the hybrid inverter, therefore, an additional automatic transfer switch is required in the system.
Low Battery SoC Activation
During the off-grid condition, when the battery SoC is lower than the value of “Start SoC”, the system will disable the EPS output and then the dry contact will continuously offer a 12Vdc power to activate the generator. After the battery is charged to the “End SoC” or the grid power comes back, the system will stop offering a 12Vdc to the generator, and then recover the EPS output
Note: If the battery system is the lead-acid battery, then the system will operate according to the start and end voltage.
Note: To avoid switching on/off the generator frequently, the minimum working time of the generator is ten minutes.
During the off-grid condition, when the user enables the manual activation, the system will disable the EPS output and then offer a continuous 12V power to activate the generator. And the dry contact will stop offering a 12V power and enable the EPS output when disabling the manual activation
The users can realize multiple control modes of the water heater and generator by GROWATT dry contact solution. On the one hand, it can help the users to boost the solar self-consumption rate and reduce the electricity bills further, on the other hand, it can help users to guarantee the 24 hours power supply when a blackout happens.