Why does a chiller trip

by John C. Schaub

You have in fact merely gotten a phone call from a new consumer that has a problem with a production fridge. The best suggests to help begins before you get to the jobsite.

1. The main action is to call the customer in addition to ask for details worrying what occurred, in addition to what signs or codes show up on the evaluation readouts (if the fridge has any kind of sort of). If the customer does not acknowledge any kind of sort of details, ask him or her to examine the following:

  • Is the pump streaming the water? What is the water temperature degree?
  • When did the fridge go off-line, in addition to has this occurred before? If so, when (could it correspond time day-to-day or specific very same time once a week)?
  • Is the fridge running in addition to not cooling, or merely not executing in all?

These are critical items you can make use of as a fixing start element before you get to the jobsite. As quickly as on the scene, follow this detailed recap:

2. Check out to see whether the information you got over the phone is right.

3. As quickly as you have in fact identified the accuracy of this information, assess the apparent. Is the fridge running? If it’s running, afterwards go the activity # 8. If it isn’t, look for an evaluation display panel that can educate you a directions to begin analyzing. Does the fridge have main power in addition to control power from the transformer? Check out all the incorporates.

4. Bear in mind any kind of sort of codes described on the fridge (a great deal of the extra current fridge tools have evaluation codes or security system codes to see). Seek the consider the tools’s repairing manual. Ensure business can obtain that for you, additionally if you acknowledge the fridge. Today’s extra current fridges have a computer system’s well worth of information created right into memory.

4a. If the fridge isn’t running, find the electrical depiction of its control in addition to high voltage circuits. This will definitely be exceptionally necessary with an older fridge not prepared with incorporated diagnostics. The element a compressor does not include is usually as an outcome of an “open” issue someplace in the control circuit. You call for to find where the open issue remains. Use the electrical depiction to find it.

4b. Begin at the power side of the transformer in addition to examine wire by wire. On those job where you do not have ease of access to the electrical depiction, or when the fridge depends on a location where you can not have a look at variation numbers or see any kind of sort of evaluation indicator lights or codes, frequently start at the control transformer in addition to follow the control power line training course. Discover the power side, in addition to with an excellent voltmeter, trace the power line from safety to safety. Eventually the control power will definitely worry the compressor or pump contactor coil.

An extra methods to do this is to work backwards from the compressor contactor control coil to the control transformer. It’s along these programs that you’ll find the open circuit, if there is one.

5. If you find an open issue, afterwards you require to determine why. Possibly anything from minimized tension to a harmed compressor control part.

Fridges usually have 2 unique safeties: One is a water flow switch, which can be hidden in the water piping in addition to disappoint up, particularly if you have a remote pump tank system. The second safety is a freezestat control. A freezestat is usually a back up thermostat that makes certain the supply water temperature degree does not get also freezing. Typically freezestats are developed 10 F a lot less than the supply water temperature degree the customer wants to run.

6. Make a visual exam of the fridge electrical panel, water piping, in addition to pump tank system (if it has one). You could have the capacity to see apparent concerns such as dissolved or broken cables, the water pump not running, water shutoffs closed down, in addition to inaccurate system water temperature degree.

7. Presently, you need to have situated which safety stumbled. Do not reset it till you have your assesses on the compressor in addition to oil pump (if appropriate). Strap temperature degree probes on the suction, discharge, in addition to liquid lines. Placement an amp meter on the high voltage leg of the compressor before you start the system. Reset the safety. Afterwards take pleasure in all the tension, temperature level degrees in addition to amperages at the specific very same time. This is not an easy work, yet necessary, particularly within the preliminary 5 minutes. Miss to point #10

8. Activity the antifreeze emphasis in the system. If the system does not have antifreeze, afterwards examine the water top-notch. The best suggests to establish antifreeze is with a refractometer Bear in mind, if the system makes use of ethylene or propylene glycol, the freeze element will definitely be different for the specific very same percents. If you search the internet to this net address, you can check out a comparison table to see the differences: More than likely to

9. The fridge is running. Terrific! Presently place assesses in addition to temperature degree probes in addition to begin taking evaluations. Presently you lead the computer game, yet not out of the woods. You call for to find why the system either stumbled a protection or isn’t running the suggests the customer requires.

Normal Fridge Fixing Difficulties

Following are some typical concerns that you can repair, based upon the evaluations from your assesses in addition to probes:

A. Low tension trip— Caused by minimized air conditioning representative, power establishing harmed capillary; minimized or no water flow; obstructed water filter or screen; antifreeze or mud coating tvs of the evaporator setting off insufficient efficiency.

B. High tension trip— The water-cooled condenser has insufficient or no flow; water-cooled condenser has mineral accumulation as an outcome of insufficient water top-notch (exceptionally typical); air-cooled condenser is blocked with fragments or has a fan not operating; cooled down water tank temperature degree is exceptionally high (over 80 F as well as additionally).

C. Oil falling short trip— Can be induced by either minimized superheat, minimized oil (as an outcome of an air conditioning representative leak), or oil pump problems.

D. Freezestat— Poor water flow, or the thermostat is developed also minimized.

E. Blown incorporates or starter trips— Shorted or over-amped electrical motor, compressor or cables. Ensure to seek properties or shorts before you try once again.

F. System running yet not reaching thermostat setpoint— Evaporator inside chilly up, antifreeze failing setting off insufficient heat exchange, system heaps is excessive for fridge to take care of.

G. Proof of flow— either flow or tension switches in water circuit are fighting with minimized or no flow, blocked water filter, water shutoff closed down, water piping also little, flow switch paddle harmed (exceptionally typical).

Keep in mind that these dominate, yet never all the concerns that can cause a fridge to go offline. It’s frequently best to remain to be upgraded on fridge technology with training. All the considerable fridge manufacturers supply repairing universities in addition to workshops. All organization location service professionals need to get themselves of them.

Why does a chiller trip

Additionally when your fridge is examined in addition to maintained regularly, its performance can deteriorate or deteriorate with time. Pumps can quit working, treatment lines can obstruct, cooling down representative can leakage, in addition to any kind of sort of selection of concerns gotten in touch with aspect aging or modifying environmental issues can occur (table 1).

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Following are some initial activities to call for to help different the difficulty:

  • Make Sure that the fridge is running. A blown breaker or fuse, loosened up wiring, or simply a power switch that’s been put in the “off” positioning can be safeguarding versus the fridge from running.
  • Determine whether the fridge is cooling off. Check out the temperature degree of the coolant at the fridge’s electric outlet to the treatment. If it isn’t at or near the setpoint temperature degree, the evaporator can be chilly up or the heat transfer property or industrial residential properties of the coolant fluid can be deteriorating.
  • Validate that the pump is running. A closed or partially closed shutoff, quit working pump, inadequate coolant amount or treatment line restraint can be safeguarding versus the adequate flow of liquid with the treatment coolant technicality.
  • Check out the treatment in addition to environmental issues. The heaps on the fridge can be excessive as an outcome of changes at the very same time or the ambient temperature degree. Numerous various other issues that can affect the fridge’s heat removal abilities contain an alteration in the location of the fridge (near different other heat-generating tools or additionally from the treatment tools); loose, hurt, or losing out on insulation on the piping in between the fridge in addition to the treatment; or adjustments in line voltage.

Normal Fridge Difficulties in addition to Viable Factors


  • Unacceptable line voltage or loosened up web link
  • Incorrect phase web link (three-phase tools)
  • Blown breaker or fuse
  • Power switch in “off” positioning


  • Improper or fluctuating line voltage
  • Insufficient fluid in tank
  • Pinched or minimal treatment line
  • Close or partially closed treatment shutoff
  • Coolant fluid inappropriate for temperature degree needs
  • Clogged fluid filter
  • Improve piping also little
  • Refine restraint
  • Pump falling short


  • Improper or fluctuating line voltage
  • Obstructed air filter or condenser
  • Coolant fluid inappropriate for temperature degree needs
  • Cozy transfer property or industrial residential properties of the coolant fluid have in fact worn off
  • Air conditioning representative leak
  • High ambient temperature degree
  • Evaporator cold up


Why does a fridge trip?

Lowered tension trip– Caused by minimized air conditioning representative, power establishing harmed capillary; minimized or no water flow; obstructed water filter or screen; antifreeze or mud coating tvs of the evaporator setting off insufficient efficiency.

What is the method temperature degree?

What is “Technique Temperature degree”? This term defines the temperature degree difference in between the leaving treatment fluid in addition to the entering into service fluid. If air is cooled from 300 F to 100 F using 90 F cooling water, the air temperature degree resembles the water by 10 F (100– 90 = 10).

What is evaporator method in fridge?

Evaporator method is the difference in between evaporating temperature degree determined at the well in the evaporator, in addition to leaving cooled down water temperature degree. Condenser method is the difference in between liquid air conditioning representative temperature degree as determined on the liquid line, in addition to leaving condenser water temperature degree.

Which chemical is used for descaling in condenser?

Descaling reps are frequently acidic compounds such as hydrochloric acid that react with the calcium carbonate in addition to magnesium carbonate compounds existing in the array, creating carbon dioxide gas in addition to a soluble salt.

What type of water cooled condenser is used in significant fridges?

A normal water-cooled fridge makes use of recirculating condenser water from a cooling tower to condense the air conditioning representative. A water-cooled fridge contains an air conditioning representative relying on the entering into condenser water temperature degree (in addition to flow cost), which operates in link with the ambient wet-bulb temperature degree.

What are type of fridges?

There are 3 different type of fridges: (1) air, (2) water, in addition to( 3) evaporative pressed fridge. There are 4 subcategories in each of the above categories for industrial fridges: (1) reciprocating, (2) centrifugal, (3) screw driven (4) in addition to absorption fridges.

Is a fridge a condenser?

A fridge gets rid of heat from a liquid with a vapor-compression or absorption refrigeration cycle. Air-cooled fridges are usually outdoors in addition to include condenser coils cooled by fan-driven air.

What are the type of condenser?

The considerable type of condensers used are (1) water-cooled, (2) air-cooled, in addition to (3) evaporative. In evaporative condensers, both air in addition to water are used. 3 typical type of water-cooled condensers are (1) double pipe, (2) covering in addition to tube (as gotten Fig. 6.9), in addition to (3) covering in addition to coil.

What is the idea of condenser?

The goal of the condenser is to get the high-pressure gas from the compressor in addition to change this gas to a liquid. It does it by heat transfer, or the idea that heat will definitely frequently transfer from a warmer to a cooler substance.

What is using condenser in aircraft?

The condenser looks like a radiator consisted of a superb dimension of tubes with fins attached to promote heat transfer. Outdoors air is led over the condenser. The temperature degree of the air conditioning representative within is greater than the ambient air temperature degree, so heat is relocated from the air conditioning representative to the outdoors air.

Which type of condenser is best for cooling?

Copper has a heat transfer coefficient greater than aluminium. That shows, copper is a much much better heat exchanger than aluminium. 2) Rate in addition to Pliability (The top-notch of being easily bent): Copper is extra costly than aluminium, which improves the expenditure of making a cooling system in addition to therefore the expense of a/c system.

Which type of coil is best for cooling?

Copper is a much much better heat exchange than aluminium coils shows copper coil can cool off the location much quicker, successfully than aluminium coil. This makes a/c system a whole lot extra electric power preserving one.

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Compressors of fridge trip upon start

Compressors of fridge trip upon start

At our work we have 2chillers 90 whole lots cooling off capcity, i supplied it with power from 1600 kva transforer 20/ 0.4 kv,50 HZ,6.4, oil kind
there are an extra family 1000 amps
Great deals connected to the transformer, according to my study the required cable measurement for 80 m lengeth from the TR to the fridge panel is 3 150+95 NYY for every and also every fridge, the difficulty is that: considered that each fridge has 4 compressors in addition to it start in addition to stop on a regular basis it
Journeys, need to i improve the cable size?the optimum existing brought in by one fridge( 4compressors running) is
200 amps
Lots of many thanks in advance

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

my form is that: upon compressor start, the protection of the compressor locate that an unacceptable voltage decrease took place in addition to it figures out the compressor professional to trip, please find affixed the security system schedule, i frequently get security system T51 IN ADDITION TO T55

RE: Compressors of fridge trip upon start

Hello There There Elec777; You could be having a look at the inaccurate issue. The security system affirmation for T51 or T55 is that:


These issues oblige the trips of the breaker( s) not that the breakers are stumbling from stressing.

Have you checked out the standing of:
1) High tension switch?
2) Loss of charge minimized tension switch?
3) Loss of condenser air?
4) Liquid shutoff closed?
5) Have you checked out that the control relay is running which it’s attached right into its electrical outlet safely?
6) Any type of sort of signs on the CPCS board in addition to are they disclosing any kind of sort of job?

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

Howdy Elec777,
Undoubtedly the compressor OEM would definitely find blunder with the power supply. Precisely just how does the OEM support this affirmation? Has he been to the Web site?
80 m of 150 mm-sq conductor measurement need to not be supplying any kind of sort of worries wrt voltage decrease.
q1) Does each compressor start subsequently? (ie They do not all start at the specific very same time.)
q2) Did you establish the voltage-drop at the compressor panel throughout a start duration?
q3) Precisely just how significant is the generator system? Precisely just how is it connected to the compressor panels? (a 1-line would definitely be helpful)

” I have in fact not failed. I have in fact merely situated 10,000 way ins which will certainly not work.” Thomas Alva Edison (1847-1931)

RE: Compressors of fridge trip upon start

Electric electric motor currents:
436 Amps
436 Amps
468 Amps
65 Amps
Fans 3.4 x 6 = 20.4 Amps
General heaps 219.4 Amps

General capacity needed:
Preliminary fridge 220 Amps
second fridge 220 Amps
Base heaps 1000 Amps
General capacity = 220 Amps + 220 Amps + 1000 Amps
1440 Amps.
1440 Amps x 1.73 x 400 Volts/ 1000 = 998 KVA (The generator would definitely call for a lot more capacity.)
Have you determined the voltage decrease on your feeders?
Have you determined the voltage dip or droop at the transformer terminals when a 65 Amp compressor starts?
You could have a “soft” 20 kV supply.

RE: Compressors of fridge trip upon start

I accept GG that 80 m of 150 mm ² cable must not be the factor for a volt-drop difficulty with a 200 A lots, considered that there are not a trouble with the installation.

Use a details logger. Get genuine existing in addition to voltage details as opposed to assumption.

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

Quote (waross)

RE: Compressors of fridge trip upon start

Priceless Waross,
in addition to considered that tiny supply voltage at our internet site is 380 v/3ph/50 HZ, therefore I am presently out of the voltage worth required by the compressor(400 V not 380 V), so I try to convience the power developers to inncrease their voltage to 400 volts.

apriciate your concern

RE: Compressors of fridge trip upon start

Quote (Elec777)

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

RE: Compressors of fridge trip upon start

The difficulty looks like relentless minimized voltage.
Among one of the most monetary treatment is to place a collection of autotransformer rise transformers in open delta.
Capacitors are outstanding for responding to receptive voltage decreases. I do not think that that is your difficulty.
Capacitors will definitely enhance the voltage once the receptive current is ended, added increases in voltage are not outstanding in addition to not affordable.
It could be possible to place sufficient capacitors to enhance the voltage from 380 Volts to 400 volts yet you will definitely afterwards have a whole lot capacity placed that:
You could maintain power facet penalties.
You could be stressing your service with capacitive existing.
Your Principal Financial Cop could be shouting worrying the capital expense.

Perfect in addition to a lot of affordable treatment is the “open delta car transformer rise”.
Many affordable yet not finest is to reduce the under-voltage trip configuration on the controls.

RE: Compressors of fridge trip upon start

Is the transformer not prepared with taps? I have in fact never ever before seen a 1600 kVA transformer that did not have (+/ -2.5% & +/ -5%) taps.
If you truly have a LV difficulty, why not improve the voltage by 5% (ie from 380 V as high as 400 V). You furthermore call for to ensure that you do not take a look at voltage.
I do not remember what the voltage resistance is for IEC electrical motors, nonetheless, for a standard NEMA electrical motor it is +/-10%. (ie a 400 V NEMA placed electrical motor can supply NP power from 360 V as high as 440 V).

” I have in fact not failed. I have in fact merely situated 10,000 way ins which will certainly not work.” Thomas Alva Edison (1847-1931)

RE: Compressors of fridge trip upon start

I exceptionally doubt my competent suspicion listed below. Yet location it forth.
Remembering the tools sticker label in an earlier post stands for the tool is placed as a singular voltage device.
I’m asking on your own if it left the production center with the electrical motor connected to go for a different voltage.
Strange individual factors have in fact happened.

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Fridge surge is a trouble in which air conditioning representative streams in reverse from the condenser back to the compressor, which can trigger severe problems.

What Is S wish?

Each fridge system has a maximum lift (head tension), which is the difference in between condenser air conditioning representative tension in addition to evaporator air conditioning representative tension. Elevate can furthermore be determined by the difference in between the leaving chilled-water temperature degree (LCHWT) in addition to the entering into condenser-water temperature degree (ECWT). If this differential increases to where it exceeds the system’s pumping capacity, cooling down representative will definitely stream in reverse with the compressor wheel every number of secs. Stress and anxiety builds up in the compressor, setting off the air conditioning representative to climb forward once again, in addition to the cycle repeats. This reverse-load can damage the drive establishing, bearings in addition to transmission, in addition to can cause a tear in the safety disc or blow the safety and security shutoff. Increase is identifiable by its loud, distinct sound, sometimes contrasted to an elephant’s screech or an increasing jet engine, along with a variant in compressor amperage.

What Produces Increase?

Fridges are developed to accomplish particular system requires in addition to running issues. With appropriate maintenance in addition to treatment within design intent, an appropriately chosen fridge will definitely not climb. Changes in running issues, nevertheless, can cause surge to occur, particularly under minimized heaps issues. Increase can be attributed to maintenance worries including fouled tubes, minimized cooling down representative charge, or non-condensables in the air conditioning representative. It can furthermore be induced by insufficient control of water flow rates in addition to condenser water temperature level degrees. Lowered heaps worries (surge worries) can be avoided or fixed with cozy gas bypass or VFDs.

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