Understanding Electronic Controls Diagrams

Transcription

1 Understanding Electronic Controls Diagrams 1

2 DC Circuit Rules 2

3 Inputs VS outputs Micro processors 3

4 Troubleshooting Tools Jumper Wires Circuit Breaker Diode 50 KΩ potentiometer 500 Ω Resistor 9 VDC battery 115 VAC patch cord 24 VAC power supply Good HVAC VOM meter 4

5 Control Testing 5

6 Binary or Digital 6

7 Analog 7

8 Analog 8

9 The ANALOG meter can detect all of the steps between the numbers, so the needle moves smoothly. Try to get the DIGITAL meter to go between numbers! You can't!

10 The Numbers Meg or M = x 1,000,000 K or Kilo = x 1,000 1m or milli = x.001 (1000x.001=1)Thousand to make 1 m( ) or Micro= x ( x =1) Million to make 1 p or pico = x (billion to make 1) n( ) or nano = x (trillion to make 1)

11 PWM 11

12 Power circuits 12

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22 Microprocessor Packaged roof top Systems 22

23 Get to know your Module 23

24 RTRM LED Functions EXAMPLE Green System LED ON: Normal operation Blinking: Test Mode OFF: No power or board failure Green Transmit LED Very Fast Flash: Normal operation, communicating OFF: Board failure Yellow Receive LED Very Fast Flash: Normal communication Wink Every 2 Seconds: No comm with other modules OFF: Board failure

25 IGN LED Functions EXAMPLE ON: Operational with no call for heat Flashing: Active call for heat 1 Flash: Not communicating with RTRM 2 Flash: Heat Lockout (fail to ignite, no spark, low gas pressure, etc) 3 Flash: Pressure Switch input (no airflow, bad CBM, etc) AUTO RESET 4 Flash: High Temperature Limit input AUTO RESET 5 Flash: Flame sensed when gas valve is not energized 6 Flash: Flame Rollout switch MANUAL RESET AT SWITCH

26 Inputs & Outputs 26 BIP 0-28 VAC (CC status, LPC, Etc). BOP 0-28 VAC (CC, FC, ODF, SOV, Etc.) AIP 0-5 VDC (Temp Sensors) 4-20 MA (Humidity sensor) AOP 0-5 VDC 0-10 VDC (C02) VDC (Status)

27 Wiring 27

28 Snubber Circuits 28

29 CC1 out Remove J4 IF not working in test mode 24 VAC in 5 DC 5 DC 2-3 v flashing 24 VAC 24 VAC out 0-32 VDC 24 VAC in Config pt. to common > 2000 Ω when open VDC

30 24 VAC when open Deumd Sp 24 VAC when open 24 VAC when open Deumd Sp Test points 5 VDC 4-20 ma VDC 30

31 5 DC 4-20 MA DC 0-10 VDC 31

32 Temperature deg 32

33 Setpoint 33

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35 35 ECA Humidity Sensor VDC

36 Mode 36

37 Differential Pressure Transducer A differential pressure transducer is used with both Analog electronic and Direct Digital Controls. Its function is to convert a delta pressure signal that can be monitored by the controller during pressure independent operation. 37

38 Differential Pressure Transducer Input inch WC Operating temp.-32f-+140 F Storage temp 40F- +180F Voltage Vin =5VDC 38 Null=.250 VDC /- 60 mv Span VDC +/- 80mv

39 Pressure Transducer The relationship of voltage to pressure is 0.75VDC per 1" of pressure. Since the 0" voltage is 0.25", 1" of pressure = 1VDC. 2" of pressure = 1.75VDC VDC 5 VDC

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41 41 MMC Manual Motor Control

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44 Heating 44

45 IGN. Wiring (Trane) 45

46 IGN. Wiring (FenWal) 46

47 IGN. Wiring 47

48 IGN. Wiring 48

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50 ECM motor 50 3 PH DC Motor Aprx. >12 Ω Winding to Winding

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54 Waterfalls and Circuits: More in common than you think Electrical Circuits can be thought of as a waterfall Voltage (V) Height of Waterfall Measured in volts Amperage or Current (I) Amount of water falling at one point at any moment Measured in amperes Resistance (R) Constriction of water Measured in ohms

55 Troubleshooting Need good meter Need to know sequence of events Need to know system operational parameters Don t reset power tell you check for codes! 55

56 Microprocessors Manufacturers use microprocessors to Reduce costs Make products more reliable Make products less compacted Easier to troubleshoot Reduce recourse required for the product The reduction in wiring and controls as a result of microprocessors is often called Clean Technology A microprocessor is simply a computer with a sequence of operation programed into it 56

57 Troubleshooting The first step in troubleshooting is RTFM ( read the manual) Many microprocessors have built in self-diagnostics Codes in the form of flashing LED s or LED display Clear language displays Software products to connect to processors Many microprocessors have built in test functions Enables technician to go through system functions Most of the time input signals are low voltage AC or DC 57

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59 Inputs/Outputs BIP (24 vdc & Optical inputs) 2. BOP (120 & 24, Triac s etc. ) 3. AIP (0-5,0-10, & 4-20 ma) 4. AOP (2-10 & 4-20ma) Communication

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64 Modules 64 LLID s BIP (24 vdc & Optical inputs) BOP (120 & 24, Triac s etc. ) AIP (0-5,0-10, & 4-20 ma) AOP (2-10 & 4-20ma) Communication Smart Sensors

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74 Variable Frequency Drives

75 Root reason for using VFD As you change motor frequency you change motor speed. If you change motor speed you change motor horsepower. Every horsepower change is 746 watts saved. 75

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78 Why use a VFD Variable frequency drives (VFDs) allow motors to adjust their speed to better match the actual load. VFD s change the speed of the motor by using semiconductor switching devices. VFD s are ideal for motors driving variable torque loads often found in variable flow applications.

79 VFD sections Regulator Controls the rectifier and inverter to produce the desired ac frequency and voltage. Rectifier Converts the fixed 60 Hz ac voltage input to dc. Inverter Switches the rectified dc voltage to ac, creating variable ac frequency (and controlling current flow, if desired).

80 Benefits of VFD Efficient means of modulating the output of conventional induction motors and synchronous motors. Make it practical to use precise motor speed in a wide variety of applications. VFDs offer the best turndown ratio. Some of the new models approach the near-zero-speed capability of DC drives. Low maintenance no moving parts other than pushbuttons. Ease of installation and retrofit.

81 Limitations VFDs waste more energy as heat, particularly when there is significant speed reduction. The VFD does not deliver a true sine wave voltage to the motor. Harmonics may be an issue. VFDs increase losses in the transformers that feed them because of distortion of the input waveform. Some VFDs may cause existing motors to run substantially hotter. Not usable with conventional ac motors in applications where the motor must maintain high torque as the speed is reduced. Conventional motors lose their ability to get rid of heat as speed is reduced (limitation of the motor rather than a limitation of the drive.) Motors need to have cooling independent of motor speed, which is typically a special requirement. Overall system efficiency of modern dc drive systems and variable-pulley drives can be higher than the system efficiency of VFDs on induction or synchronous motors.

82 VFD Introduction VFDs convert AC to DC then DC to AC (at varying frequency and voltage) AC DC AC Rectifier Inverter 460 V, 60 Hz 640 V, DC 307 V, 40 Hz VFDs allow the motor to operate and consume electricity as if it were the right sized horsepower for the job.

83 Drive Layout Input PWR Quality Output

84 Layout

85 Components Rectifier Inverter Power Quality

86 Magic Component's Regulator Electronic controls Filters Lots of Magic in the boxes which in realty is just electronics switching between 0 and 1.

87 Period, range of q Diode Pair in conduction 30 o to 90 o D 1 and D 6 90 o to 150 o D 1 and D o to 210 o D 2 and D o to 270 o D 3 and D o to 330 o D 4 and D o to 360 o and 0 o to 30 o D 5 and D 6

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91 Safety Stop

92 Trane TR-200

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