Table of Contents
Advertisement
u
Differential Pressure Switch
Differential pressure switch is used for checking the lubrication problem. When the differential pressure between
the condenser and evaporator is higher than the set value (4kgf/cm
2
), the switch will be closed. On the other
hand, if the value is below the set value, the switch will be open. This switch will automatically be closed when
the differential pressure is recovered to below set value.
Fig. 25
In the following cases, differential pressure switch works frequently.
1) In case of which condensation temperature is too low because of low outdoor air temperature
2) In case of which cooling water temperature is too low because of cooling water flow rate is too high
3) In case of which cooled water temperature doesnʼt lower, because of cooled water flow rate is too high
4) In case of which cooled water temperature doesnʼt lower, because cooling load is too high
In this case, an operator operates the machine to generate discharge/suction pressure difference by controling
cooling tower fan, cooling water flow and cooled water flow in the equipment following direction.
1) Install 3-way valve to control cooling/cooled water flow rate
2) Use Inverter type pump to control cooled water flow rate
3) Control cooling tower fan by manual until cooling water temperature reach proper status
- 53 -
Operation & Maintenance Manual
Advertisement
Table of Contents
