A.
Chiller shuts down on high refrigerant head pressure. |
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B.
Chiller shuts down on low refrigerant pressure. |
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C.
Chiller shuts down on low flow. |
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Not enough water flow.
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Faulty flow switch.
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Chiller
is not maintaining set point temperature. |
A.
Cooling load is too high. |
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B.
Incondensable in the refrigeration circuits. |
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Call refrigeration mechanic.
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C.
Evaporator is old or plugged. |
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Call refrigeration mechanic.
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1.
Water temperature too warm. |
A.
Cooling Tower Fan not operating. |
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Motor is burned out.
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Fan belt is broken or loose.
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Fan shaft is broken.
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Fan blade(s) or blower is broken (usually caused by
freezing).
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Fan thermostat is broken.
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Fan thermostat is set too high.
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Fan motor fuse needs replaced.
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Fan starter overload needs replaced.
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B.
Not enough water flow across Cooling Tower. |
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Check Tower Pump discharge valve is not closed.
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Check Tower Pump suction valve is not closed.
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Check if Tower Pump is operating.
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Check to see if wet deck or Tower nozzles are not plugged.
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C.
Too much water flow across Cooling Tower. |
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Is Tower Balancing Valve wide open?
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If
Standby Combined Pump is being used, is discharge valve wide open (too
much pressure) or throttled to simulate Tower Pump?
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D.
Tower Fill is in poor condition |
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E.
Cooling Load is too large for existing Cooling Tower. |
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Do Cooling Load Analysis.
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2.
Cooling Tower water temperature too cold. |
2.1
Tower Fan is not cycling off. |
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2.2
Small cooling load and very cold temperatures. |
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Is
low temperature thermostat not turning Tower pump off? (For
primary/secondary systems)
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Is low temperature thermostat not causing the Tower Water
to bypass the Cooling Tower? (For single loop systems)
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3.
Is Cooling Tower Water in poor condition? |
3.1
Water Treatment System |
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Is the water make-up meter working? (This cycles the
chemical pumps.)
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Are the chemical pump timers adjusted properly? (Too much
chemicals.)
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Is the conductivity probe measuring accurately? (Needs to
be cleaned periodically.)
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Is the water bleed-off valve operating properly? (Solenoid
valve may not be working or the valve may be plugged with sediment.)
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Is the Water Treatment controller working properly?
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Are you dumping too much city water into the system?
(Throws the chemical treatment system off.)
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3.2
Do you need a water softener? |
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3.3
Do you have proper water filtration? |
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Do you have full flow strainers? (Usually 1/16” for
discharge strainers and 1/8” for suction strainers – placed in supply to
process.)
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Do you have fine particle filtration set up as a bypass?
(Usually 5% of the flow to process. Allows the filtration of the fine
particles which reduces the bleed-off and the amount of water make-up and
chemicals needed.)
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1.
Not enough flow to a process. |
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Pipe is undersized for the application. ( A flow analysis
is needed to ensure water is not being restricted because of undersized
pipe.)
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Pipe is plugged. (May need to be cleaned or replaced.)
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Valve is closed.
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Process Pump is undersized for flow requirement. (Need to
do a cooling load and flow analysis of system.)
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Valve is wide open in another part of the system and is
robbing all of the flow.
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2.
Not enough pressure to a process. |
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Pipe is undersized for the application. (Too much pipe
pressure losses.)
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Pipe is plugged. (May need to be cleaned or replaced.)
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Valve is closed.
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Process Pump is undersized for pressure requirement.
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Valve is wide open in another part of the system and is
robbing all of the flow. (And therefore, the pressure.)
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3.
Water hammer is causing pipe to leak. |
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Water hammer is normally caused by a sudden change in
pressure where the pressure differential is large. In a large piping system,
there are many reliefs (open valves) to absorb the water hammer. However, if
water hammer persists, there are many ways to fix it. |
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Properly support pipe. (A small water hammer can cause
water pipe to sway.)
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Change on/off solenoid valves to slow actuating or
modulating valves.
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Soft starters on pumps.
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Water hammer arrestor should be installed.
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City water pressure reducing valve before water make-up
valve.
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