HVAC Compressor Replacement. Terry Bell, Carmichael Engineering Ltd. Moderator: Daniel Gardiman, Carmichael Engineering Ltd.

Transcription

1 HVAC Compressor Replacement Terry Bell, Carmichael Engineering Ltd. Moderator: Daniel Gardiman, Carmichael Engineering Ltd.

2 Agenda This session will walk you through the steps required to replace an air conditioning compressor and review best practices to ensure system reliability. During the session, we will discuss common system accessories, their function and common failures. Objectives: Discuss the roots of refrigeration Breakdown the TON Introduction to various compressor categories and styles Illustrate the steps required to replace a compressor

3 History of Refrigeration

4 What is this TON we reference? 1 short ton (Imperial) weighs 2,000 lbs Energy required to make or melt 2000lbs of ice at 32F (0C) = 288,000 BTU in 24 hours 1 Ton (TR) = 12,000 British Thermal Units/Hour (BTU/h)

5 Refrigeration Cycle

6 Compressors

7 Compressor Classifications Open belt driven by an external motor Semi-hermetic motor and compressor contained within same body, can be opened and the internals can be replaced Hermetic motor and compressor contained within same body, sealed and cannot be opened

8 Compressor Types Scroll Compressor Hermetically sealed one fixed scroll, one rotating scroll

9 Compressor Type (cont d) - Reciprocating Compressor Either Open, Hermetic or Semi-hermetic Similar to an engine, piston and cylinder arrangement

10 Compressor Types (cont d) Screw Compressor Rotary Compressor Centrifugal Compressor

11 Compressor Failures

12 Common Compressor Failures Refrigerant slugging Breaks internal components of compressor Worn Bearing Causes internal damage

13 Common Compressor Failures cont d Broken Valves Typical result of slugging Long periods of unloaded operation Too much oil Motor Electrical Failure Poor power supply Over heating

14 System Failures Causing Compressor Failures Debris within the system Block refrigerant flow Score/damage internal surfaces Low refrigerant/refrigerant leaks Reduced refrigerant to cool the motor Reduced oil to lubricate the motor Higher internal temperatures

15 Compressor Replacement Process

16 1. Refrigerant Recovery The process of removing the refrigerant from the circuit o Tools Required: o Recovery unit o Recovery bottle o Scale o Extension cords

17 2. Compressor Removal / Installation otools Required: ohand Tools otorches ofire Suppression oppe

18 Brazing Techniques Purge with nitrogen while brazing Reduces oxides inside the pipe which prevents carbon What type of joining material should be used? Solder, low melting point filler used to join copper, brass Sil-Fos, used as filler material to join copper-copper Silver, used for dissimilar metals (copper, brass, steel)

19 Accessories to Consider Filter Driers (Suction and Liquid) Solenoid Valves System Screens (refrigerant and oil) Oil (Mineral or Polyolester (POE))

20 3. Pressure Test / Leak check Pressurize the unit/circuit with nitrogen to the maximum pressure of the low side of the circuit Leak check Liquid soap Electronic Dye / Ultra-violet light Listen

21 4. Evacuation What temperature does water boil at? 100 C or 212 F Can we make water boil at room temperature? Water + oil + heat = acid Water + low temperatures = ice (restriction)

22 5. Refrigerant Charging

23 Wrap Up Know what you re looking at when looking at equipment Understand proposals supplied by service providers Understand the process to replace a compressor

24 Resources To download, visit

25 PRSM Resources: Toolkits: HVAC Includes Guides, Tools, Education and Resources. Best Practices Books 2010 thru 2015 HVAC Topics 2015: HVAC Preventive Maintenance/Minor Repair Training Program (HVAC-PM/MR-TP). 2014: HVAC Maintenance: The Old and The New 2012: HVAC Maintenance and Repairs Quote Review.. On-Demand Webinars: Retail Facilities 101: HVAC Professional Retail Store Maintenance Magazine 2015 Tips Issue, Page 6,8 and 11 HVAC Topics

26 Q&A Terry Bell National Accounts Technical Supervisor Carmichael Engineering Ltd.