The PAK can control up to 4 condenser fan groups containing up to 8 total condenser fans. The PAK con- denser control strategy is sequential TD control with set- point/deadband using ON and OFF delays.

The PAK has a compressor/condenser interlock fea- ture that will override TD control and force the condenser fans to stage off using the TD control OFF delay when all compressors are off. This feature can be disabled with an Enable/Disable setpoint or when the discharge pressure is above a configurable setpoint.

The MultiFlex PAK boards consist of two circuit

boards: a bottom layer with 16 combination digital/analog inputs, and a plug-in top layer which contains a combina- tion of 8 relay outputs and 4 digital DC voltage outputs.

The analog outputs on the Multiflex PAK drive solid state relays to control the fan stages. The relays control the compressor groups.

The communication interface is RS485 I/O using the Standard Extended Address Form for Retail Solutions Dis- tributed Controllers. Currently, the PAK is designed to interface with the Retail Solutions E2 controller.

LEGEND

1

INPUT POWER

9

RS485 TERMINATION

 

(24VAC)

 

JUMPERS

 

 

 

 

2

RS485 I/O NETWORK

10

HAND-HELD

 

 

 

TERMINAL JACK

3

PAK INPUTS 1-8

11

RELAY OUTPUT

 

 

 

CONNECTORS

4

PAK INPUTS 9-16

12

RELAY OUTPUT FUSES

 

 

 

(2A rated, 250V slow-

 

 

 

blow)

5

NETWORK ID DIP

13

RELAY STATUS LEDs

 

SWITCH (S3)

 

 

6

INPUT TYPE DIP

14

RELAY FAIL-SAFE

 

SWITCHES (S1, S2)

 

SWITCHES

7

BOARD STATUS LEDs

15

PAK ANALOG

 

(Code A, Code B, General

 

OUTPUTS 1-4

 

Status)

 

 

8

DC POWER OUTPUTS

16

NETWORK STATUS

 

(3 at +5VDC, 1 at

 

LEDs

 

+12VDC)

 

 

Table 2-9- MultiFlex PAK

2.2.3The MultiFlex ESR Board

The MultiFlex ESR Valve Regulator board (P/N 810- 3199), shown in Figure 2-1,is an RS485 I/O Network electronic stepper valve regulator capable of driving up to eight stepper motor valves, which are typically used to control temperature.

3

 

10

 

 

9

7

 

 

8

 

 

1 Valve Connectors (8)

6

Termination Jumpers

2 24VAC CT 75 VAC Power Input 7 HHT Jack

3 General Status LED

8

Network Address Switches

4 I/O Network Input

9

Open LED (8)

5 TX and RX LEDs

10 Close LED (8)

Figure 2-1- MultiFlex ESR Board Layout

The MultiFlex ESR uses suction side variable-position evaporator regulators (ESRs) to vary evaporator pressure for an entire circuit and is an alternative to mechanical EPR control.

The MultiFlex ESR receives input data from a Retail Solutions E2 controller (via the I/O Network) and then regulates the stepper valves according to the data from the E2.

Each MultiFlex ESR board requires a Class 2, 80VA 24VAC center-tapped transformer for power. Retail Solu- tions transformer (P/N 640-0080) is a multi-tapped pri- mary transformer that may be used with the MultiFlex ESR board.

2.2.4Hand-held Terminal (P/N 814-3110)

The Hand-held Terminal (HHT) is used by manufac- turers and service technicians to diagnose and test several of Retail Solutions' existing and legacy products. The HHT can be used on any Retail Solutions product with an RJ-11 connector. The most common applications include:

All MultiFlex I/O boards and the 8ROSMT

All Gateway boards

Stand-alone MultiFlex boards (RTU, RCB, PAK, CUB)

2-8 E2 RX/BX/CX I&O Manual

026-1610 Rev 13 14-SEP-2011

Page 32
Image 32
Emerson E2 operation manual MultiFlex ESR Board, Hand-held Terminal P/N