What to do if the rake-type flow switch for the water pump in a chiller isn’t working properly?
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As required by the manufacturer, chillers must be equipped with rake-type flow switches on the outlet pipes of the chilled water pump and the cooling water pump. When these flow switches detect that the water flow is too low or absent, they automatically shut down the compressor and the pumps to ensure the safety of the equipment. However, after installing the water flow switch, the system keeps triggering alarms for no reason under normal water flow conditions, preventing the unit from operating. Later, the person who installed it short-circuited the water flow switch, so no alarm was triggered, even when there was no water at all. The person who installed it said that the water flow switch wasn’t good to begin with; he had installed it before and it didn’t work properly, so he short-circuited it in that case as well. But doesn’t this mean it’s no longer possible to protect the equipment, especially the compressor? Is there any good way?
This can only be resolved by the equipment manufacturer. There’s also a temperature control interlock that needs to be checked.
This post was last edited by Force ** on 2019-7-12 08:06. The water flow switch shouldn’t be related to temperature, right? I checked the working principle: The target-type (baffle-type) flow switch is used to detect unidirectional or bidirectional flow of air, oil, and water; there should be no entangled debris in the fluid. When the fluid flows through the pipe in the indicated direction, the baffle deflects; by adjusting the tuning screw, the single-pole double-throw microswitch is activated at the set flow rate, thereby generating a switch signal. During two-way detection, the baffle offset pushes the magnetic module upward, triggering the switch module to operate. It features a wide flow range setting and easy adjustment, making it widely used for measuring media such as water, gas, and oil.
I’m reminding you to pay attention to the relevant chains to see if they are related to this traffic. If the flow meter that comes with the original equipment is good, then it’s either a problem with the product itself or an issue with your purchase. There’s no need for any theoretical justification for this either.
A water flow switch is a digital switch; you can tell whether it’s working properly by using a multimeter. But this thing must not be short-circuited, especially regarding the chilled water in the evaporator; if you forget to turn on the pump, your evaporator will be damaged once it’s started up.