1、The installation shall be  performed at the  altitude less than 2000m;
2、The upper limit of ambient air temperature shall not exceed +40℃，with daily average temperature≤+35℃ and  -25≥℃;
3、The air is relative temperature at the installation site shall not exceed 50% under the higgest temperature of+40℃.  A  higgest relative 50% under the higgest temperature of +40℃。A higgest relative humidity is acceptable under a lower temperature, and monthly mean of daily minimum temperature shall not exceed +20  ℃ in the most humid month; as for this month,the average of maximum relative humidity
shall not exceed 90%,and measures must be taken for condensation formed on the product due to temperature change; 
4、installation inclination against the vertical plane shall not exceed±5;
5、Pollution grade: grade 3;
6、installation category: category  III 
Installation condition: contactor is installation surface shall have an inclination not  larger than ±5 against the vertical plane.