A switch device comprising: a first switch (120, 220, 320, 420, 520, 620) including a first blade (121, 421, 621) and a second blade (123, 423, 623) configured to selectively contact each other, wherein the first switch (120, 220, 320, 420, 520, 620) is configured to be opened based on a contact and to be closed based on a non-contact between the first blade (121, 421, 621) and the second blade (123, 423, 623); and a second switch (130, 230, 330, 430, 530, 630) including a third blade (131, 431, 631) and a fourth blade (133, 433, 633) configured to selectively contact each other, wherein the second switch (130, 230, 330, 430, 530, 630) is configured to be opened on a contact and to be closed based a non-contact between the third blade (131, 431, 631) and the fourth blade (133, 433, 633), the switch device comprising: a housing that accommodates the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 520, 630) therein; and an actuator disposed in the housing and actuated to selectively open and close the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630), wherein the first blade (121, 421, 621) of the first switch (120, 220, 320, 420, 520, 620) and the third blade (131, 431, 631) of the second switch (130, 230, 330, 430, 530, 630) are connected to a common conductor; wherein the second blade (123, 423, 623) of the first switch (120, 220, 320, 420, 520, 620) is connected to a first conductor, wherein the fourth blade (133, 433, 633) of the second switch (130, 230, 330, 430, 530, 630) is connected to a second conductor, wherein the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630) are positioned in a single inner space within the housing, and wherein the common conductor, the second conductor and the first conductor pass through the single inner space. a first switch (120, 220, 320, 420, 520, 620) including a first blade (121, 421, 621) and a second blade (123, 423, 623) configured to selectively contact each other, wherein the first switch (120, 220, 320, 420, 520, 620) is configured to be opened based on a contact and to be closed based on a non-contact between the first blade (121, 421, 621) and the second blade (123, 423, 623); and a second switch (130, 230, 330, 430, 530, 630) including a third blade (131, 431, 631) and a fourth blade (133, 433, 633) configured to selectively contact each other, wherein the second switch (130, 230, 330, 430, 530, 630) is configured to be opened on a contact and to be closed based a non-contact between the third blade (131, 431, 631) and the fourth blade (133, 433, 633), the switch device comprising: a housing that accommodates the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 520, 630) therein; and an actuator disposed in the housing and actuated to selectively open and close the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630), wherein the first blade (121, 421, 621) of the first switch (120, 220, 320, 420, 520, 620) and the third blade (131, 431, 631) of the second switch (130, 230, 330, 430, 530, 630) are connected to a common conductor; wherein the second blade (123, 423, 623) of the first switch (120, 220, 320, 420, 520, 620) is connected to a first conductor, wherein the fourth blade (133, 433, 633) of the second switch (130, 230, 330, 430, 530, 630) is connected to a second conductor, wherein the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630) are positioned in a single inner space within the housing, and wherein the common conductor, the second conductor and the first conductor pass through the single inner space. a housing that accommodates the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 520, 630) therein; and an actuator disposed in the housing and actuated to selectively open and close the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630), wherein the first blade (121, 421, 621) of the first switch (120, 220, 320, 420, 520, 620) and the third blade (131, 431, 631) of the second switch (130, 230, 330, 430, 530, 630) are connected to a common conductor; wherein the second blade (123, 423, 623) of the first switch (120, 220, 320, 420, 520, 620) is connected to a first conductor, wherein the fourth blade (133, 433, 633) of the second switch (130, 230, 330, 430, 530, 630) is connected to a second conductor, wherein the first switch (120, 220, 320, 420, 520, 620) and the second switch (130, 230, 330, 430, 530, 630) are positioned in a single inner space within the housing, and wherein the common conductor, the second conductor and the first conductor pass through the single inner space.