Schematic examples of the Safety Chain for RTU’s – Part 3

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On the first Tech-Tip we went over the R looper wire which went through Pins 7 and 8 on UCB Main like below as well as the LSM.

In the second Tech Tip of this series, we went over examples of the UCB going to a (VFD) Variable Frequency Drive.

In this one, we will discuss Commercial Air Handlers / 40RL R454B 07-12 Dissipation and EcoBlue.

Example 1: Commercial Air Handler / 40RL R454B 07-12 Dissipation and EcoBlue

Details for Example 1:

IDBC 24vac from transformer goes to UCB Main Pin 1

Smoke Shutdown A

Smoke Shutdown B

Remote Shutdown A

Remote Shutdown B

Phase Monitor (PMR) A(24v)

Phase Monitor (PMR) B(CONT)

Main Pin 7

PL12 Pin 1

PL1 Pin 8

PL1 Pin 11

PL12 Pin 2

RDB J1 Pin 5 Through R4 to

RDB J1 Pin 4

Main Pin 8

R

You now have R!

Example 2: Commercial Air Handler / 40RL R454B Dissipation With VFD

Details for Example 1:

IDBC 24vac from transformer

UCB Main Pin 1

UCB Smoke Shutdown A

UCB Smoke Shutdown B

UCB Remote Shutdown A

UCB Remote Shutdown B

UCB Phase Monitor (PMR) A(24v)

UCB Phase Monitor (PMR) B(CONT)

UCB Main Pin 7

PL12 Pin 1

PL1 Pin 8

VFD Drive ACH180 use 6/ACH580 use 25. RO1 Relay Output 1 Source (NO Power off)( NC Power on)

VFD Drive ACH180 use 7/ACH580 use 27. RO1 Relay Output 1 Source

PL1 Pin 11

PL12 Pin 2

RDB J1 Pin 5 Through R4 to

RDB J1 Pin 4

UCB Main Pin 8

R

You now have R!

Now to look at a CTB board same concept but different pins.

Note: the dark lines represent boards and controls. Notice the dark line around the IGC board as well as the dark lines around the CTB or Control Terminal Board.

On the picture above:

R Safety Circuit for CTB. CTB uses (Pin10 – Pin11)

Transformer

CTB Contl Board Pin9

CTB Smoke Shutdown A

CTB Smoke Shutdown B

CTB Remote Shutdown A

CTB Remote Shutdown B

CTB Phase Monitor A (24v)

CTB Phase Monitor B (Cont)

CTB Contl Board Pin11

CTB IFM OL A

CTB IFM OL B

CTB Contl Board Pin10

CTB R

Now you have voltage on R!

COMMERCIAL DEFROST BOARD

24vac from Transformer to ground

Note: Jumper should be on R and W1

CTB W1

CTB Reheat/HP Pin4

Defrost Board P2 Pin7

P3 Pin10

FPT Entering

FPT Leaving

CTB Reheat/HP Pin6

CTB CLO1/COMP1 Pin4

CTB CLO1/COMP1 Pin5

CTB LPS1 Entering

CTB LPS1 Leaving

CTB HPS2 Entering

CTB HPS2 Leaving

CTB CLO1/COMP1 Pin6

Contactor 24vac side.

You now have W1!

Wiring Diagram for Commercial Defrost Board

COMMERCIAL IGC BOARD (Y1 CIRCUIT WALKTHROUGH)

CTB Y1

Note: Jumper should be on R and Y1

CTB Y1

CTB Econ Pin1

CTB PL6 Pin2

CTB Pl6R Pin2

CTB Pl6R Pin5

CTB Pl6 Pin 5

CTB Econ Pin2

CTB Reheat Pin6

CTB CLO1/COMP1 Pin4

CTB CLO1/COMP1 Pin5

CTB LPS1 Entering

CTB LPS! Leaving

CTB LPS2 Entering

CTB LPS2 Leaving

CTB CLO1/COMP1 Pin6

Contactor 24vac side.

You now have Y1!

Diagram for: COMMERCIAL IGC BOARD (Y1 CIRCUIT WALKTHROUGH)

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