KSD305B

KSD305B thermostat, DPDT 20A 

Product Performance and Principle

The KSD305B thermostat produced by our company is a single-pole, normally closed type temperature controller with snap-action bimetallic discs. This controller consists of an insulated housing, metal cover, bimetallic discs, contact bridge, spring, and actuator lever.

When the temperature rises to the preset deformation temperature of the bimetallic discs, the bimetallic discs actuate through the actuator lever to separate the contact bridge from the contacts, thereby opening the switch that was originally in a normally closed state. The opening temperature can be customized according to customer requirements. After activation, manual reset is required to close the switch again.

Applications:

Applicable to electric water heaters, electric heating equipment, electric welding machines, steam generators and other high-power electrical equipment that require overheating protection

Use precautions:

Use contact temperature sensing installation. When installing, make the metal cover close to the installation surface of the heating element. Do not collapse or deform the cover during installation to avoid affecting the performance. Do not allow liquid to penetrate into the thermostat during use to avoid affecting the electrical reliability and prevent leakage damage. This product is a single-pole wiring method. When using, it should be connected correctly according to the identification symbol. The rated current should not be greater than 40A. The product should be stored in a sealed warehouse with relative humidity less than 90% and ambient temperature below 40℃, ventilated, clean, dry, and free of corrosive gases.

Electrical characteristics:

Rated Electrical Performance: AC250V 150Hz, <40A (resistive load)

Normal Electrical Strength: AC50Hz 1500V/1min without breakdown or flashover

Normal Insulation Resistance: >300MΩ

Contact Form: Single-pole, normally closed

Operation: Opens contacts when temperature rises

Durability: CQC 6000 cycles

Operating Temperature Range: 55℃-140℃

Connection Method: Secured with fastening screws

Temperature Error: ±3℃, ±5℃ (customizable per customer requirements)

Structure: Built-in type

Enclosure Protection Level: IP00

Insulation Material PTI Value: PTI175

Heat Resistance and Flame Retardant Rating: Class B

KSD305B thermostat, DPDT 20A 

The difference between SPST 40A and DPDT 20A for KSD305 thermostats lies in their electrical configuration and capacity:

SPST 40A (Single Pole, Single Throw, 40A):

Configuration: SPST means Single Pole, Single Throw. It has one set of contacts (pole) that can either be closed (connected) or open (disconnected).

Current Capacity: Rated for up to 40A (Amperes) of current under resistive load conditions.

Application: Typically used where a single circuit needs to be controlled. In the context of a thermostat, an SPST configuration might control a single heating element or a single phase of a motor.

DPDT 20A (Double Pole, Double Throw, 20A):

Configuration: DPDT means Double Pole, Double Throw. It has two sets of contacts (poles), each capable of independently switching between two positions.

Current Capacity: Rated for up to 20A (Amperes) of current under resistive load conditions per pole, totaling 40A for both poles combined.

Application: Used when more complex switching is required. In a thermostat application, a DPDT configuration might allow switching between two separate heating elements or circuits, or it could be used to control both heating and cooling devices.

Key Differences from KSD305 and KSD305B

Number of Poles and Throws: SPST has one pole and one throw (on/off), while DPDT has two poles and can switch between two different positions for each pole.

Current Capacity: SPST 40A can handle a higher current per circuit (up to 40A), whereas DPDT 20A splits this capacity between two poles (up to 20A per pole).

Application Flexibility: DPDT offers more flexibility in controlling multiple circuits or devices independently compared to SPST, which is limited to controlling a single circuit.

In summary, the choice between SPST 40A and DPDT 20A for a thermostat depends on the specific requirements of the application, including the number of circuits to be controlled and the maximum current load each circuit will draw.