Manuals / Trane / Household Appliance / Heat Pump

Trane WCY024G1, WCY042G1, WCY048G1 Demand Defrost Control Checkout, Symptoms Checks YES/NO Actions

Models: WCY036G1 WCY042G1 WCY060G1 WCY048G1 WCY030G1 WCY024G1

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DEMAND DEFROST CONTROL CHECKOUT

SYMPTOMS

CHECKS

YES/NO

ACTIONS

 

 

 

 

1. LED off.

1. 24V R-B & Y-B at board, with unit running?

N

Repair low voltage wiring.

 

 

 

 

Y

Complete Check #2.

 

 

 

 

 

 

 

2.Short FRC_DFT pin to TEST_COMMON pin.

N

Replace defrost control.

 

 

 

 

Is defrost cycle initiated?

Y

LED is bad but control will still function.

 

 

 

 

 

 

2. LED flashing very rapidly (greater

 

Y

Remove short.

than 4 times/sec) or appears to be on

 

TEST_COMMON pin shorted to TST pin?

 

 

 

 

continuously.

N

Replace defrost control.

 

 

 

 

 

 

 

3. Control does not initiate a normal

OD Temp. below 49°F.

 

Check refrigerant circuits for balanced

defrost.

OD Coil temp. below 35°F.?

N

distribution of refrigerant if OD coil is

 

"Delta" T increasing?

 

frosting and delta T is not increasing

 

 

 

 

 

1. LED flashing?

N

Refer to SYMPTOM #1.

 

 

 

 

Y

Complete Check #2.

 

 

 

 

 

 

 

2. Check for 24V Y-B at board with unit running.

N

Repair low voltage wiring.

 

 

 

 

Y

Complete Check #3.

 

 

 

 

 

 

 

3. Check sensors for correct mounting

 

Remount or replace sensor if necessary.

 

(connection) and resistance.

 

 

 

 

 

4. Short FRC_DFT pin to TEST_COMMON pin.

N

Replace defrost control.

 

 

 

 

Is defrost cycle initiated?

Y

Y-B signal or control may be intermittent

 

 

 

 

 

 

4. Control does not initiate a forced

 

N

Repair low voltage wiring.

defrost.

24V R-B & Y-B at board with unit running?

 

 

Y

Replace defrost control.

 

 

 

 

 

 

5. Defrost initiates manually but terminates in less than 10 seconds.

 

Replace defrost control.

 

 

 

 

 

 

 

6. Defrost initiates manually but

1. Coil sensor circuit open or reading at a very

Y

Replace coil sensor.

terminates on time.

high resistance?

 

 

 

 

 

 

 

2. Does OD fan cycle off in defrost?

N

Replace defrost control.

 

 

 

 

 

3. Windy weather preventing normal

 

 

 

termination?

 

 

7. Defrost initiates on approximately

Be sure OD coil is clean.

N

Complete Check #2.

15/25 minute intervals.

 

 

 

 

1. Coil sensor open or reading a very

Y

Replace coil sensor.

 

high resistance?

 

 

 

 

2. Ambient sensor reading less than normal?

N

Complete Check #3.

 

 

 

 

Y

Replace ambient sensor.

 

 

 

 

 

 

 

3. OD fan off in defrost?

N

Replace defrost control.

 

 

 

 

8. Defrost initiates on approximately

1.TEST_COMMON pin shorted to TST pin?

Y

Remove short.

30/45 minute intervals.

 

 

 

 

N

Replace defective sensor (Clear coil and

 

 

 

2. Do both sensors check OK?

reset Emergency heat light).

 

 

 

 

Y

Complete SYMPTOM #3.

 

 

 

 

 

3. Verify correct system charge.

 

Adjust as needed.

 

 

 

 

 

4. Verify a "forced defrost" terminates less than

N

Replace defrost control.

 

15 minutes.

 

 

 

 

 

 

 

 

5. OD fan motor off in defrost.

 

See SYMPTOM #9.

 

 

 

 

 

6. Verify proper SOV operation.

 

Replace if necessary.

 

 

 

 

9. OD fan runs during defrost.

 

 

Replace defrost control.

 

 

 

 

10. No SOV delay on defrost

 

Y

The soft-switch time is defeated when J1

termination.

Has J1 been cut?

is cut.

 

 

 

N

Replace defrost control.

 

 

 

 

11. ODS-A burned out.

 

Y

Check low voltage wiring for miswire.

 

1. B to T greater than 10 volts?

N

Check for short in low voltage wiring.

 

 

 

 

 

 

12. On SCROLL bearing units,

1. 24V R-B at board & 24V Y-B at board?

N

Repair low voltage wiring.

compressor does not operate.

 

 

 

2. Check protective devices in YO circuit . 24V

N

Y-B signal or control may be intermittent

 

 

YO-B present after 30 seconds.

 

 

 

13. On SCROLL bearing units, no 30

Check voltage between control terminals 2 and

 

 

second off delay at defrost initiation.

7,force a defrost cycle. Is 24V present for 30

N

Replace defrost control.

 

seconds and 0V thereafter?

 

 

Page 17

Page 16 Page 18
Page 17
Image 17
Trane WCY024G1, WCY042G1, WCY048G1, WCY036G1, WCY030G1 manual Demand Defrost Control Checkout, Symptoms Checks YES/NO Actions
Page 16 Page 18

WCY036G1, WCY042G1, WCY060G1, WCY048G1, WCY030G1 specifications

The Trane WCY series is a line of water-cooled chillers that exemplify innovation and efficiency in commercial HVAC systems. Models such as WCY024G1, WCY030G1, WCY042G1, WCY048G1, and WCY060G1 are designed to meet diverse cooling needs while maintaining energy efficiency and reliability.

One of the standout features of the WCY series is its use of advanced chiller technology, which incorporates a reliable, scroll compressor. These compressors are known for their durability and efficiency, allowing the chillers to provide cooling capacity ranging from 24 to 60 tons, making them suitable for various building sizes and applications. The efficient design of these compressors contributes to lower energy consumption, leading to potential savings on operational costs.

Another significant characteristic of the Trane WCY series is its use of microchannel heat exchangers. These heat exchangers feature a compact design that minimizes refrigerant charge and enhances heat transfer performance. The microchannel technology not only improves overall efficiency, but it also contributes to a smaller physical footprint for the units, allowing for flexible installation options in tight spaces.

The chillers are equipped with advanced controls that optimize performance, enabling users to easily monitor and adjust system operations through a user-friendly interface. The integration of Trane's Tracer™ control technology enhances operational efficiency by providing real-time data and analytics, which can inform maintenance needs and system adjustments.

In addition to these features, the WCY series includes robust construction that ensures reliability in diverse environments. The units are designed to withstand various weather conditions and are built with corrosion-resistant materials to enhance durability.

Furthermore, the Trane WCY chillers are designed with sustainability in mind. They utilize refrigerants with low global warming potential (GWP), aligning with contemporary environmental standards and enhancing the overall sustainability of building operations.

In summary, the Trane WCY024G1, WCY030G1, WCY048G1, WCY060G1, and WCY042G1 chillers represent cutting-edge technology in water-cooled cooling solutions. With their efficient compressors, innovative heat exchange design, advanced controls, and commitment to sustainability, these chillers are an excellent choice for commercial buildings seeking reliable and efficient cooling solutions. Whether for new installations or retrofits, the Trane WCY series offers versatility and performance that meets the demands of modern HVAC applications.