A mixing valve in the exchanger circulation system is controlled by the sequence.


The functionality of the pump control includes periodic pump exercise.

The Access also monitors if the pump is functional (run indication) when it is expected to run or if the pump has active alarms.


The table below shows a configuration example of the hardwired liquid exchanger.



Variable

Available options & Selection

Note


Sequence selection

Configuration > Functions > Function activation > Heating/Cooling sequence setup

Sequence for exchanger

| SEQ-A | SEQ-B Exchanger |...|



Sequence settings

Configuration > Functions > Function activation > Heating/Cooling sequence setup > Exchanger

Type of sequence

|Cooling | Exchanger | Heating | Damper | Fan setpoint compensation |


Type of exchanger

| Rotary | Plate | Liquid |


Pump control

| No | Yes |


Pump running mode

| Always running | Auto |


Type of feedback

| None | Alarm | Run indication |


Digital start output

| No | Yes |


Exchanger alarm

| No | Yes |


Type of defrosting

| None | Temperature monitoring |


Sequence output when recirculation/support

| 0% | 100% | Auto |


Sequence output min limit

0%


Sequence output max limit

100%


Sequence output when the unit is stopped

0%



PID Settings

Configuration > PID controllers > Exchanger

P-band

10 oC

PID settings for the sequence

I-time

100 s

D-time

0 s


Hardwired interface to the Exchanger's pump & valve

Configuration > I/O allocation settings >

Digital inputs > Feedback exchanger (SEQ-B)

Any available I/O

Alarm input from exchanger pump. AL-37 if the digital input is tripped

Digital outputs > Exchanger pump (SEQ-B)

Pump start signal

Analog outputs > Exchanger (SEQ-B)

Exchanger sequence output (input for valve)


Pump & Sequence control settings

Data & Settings > Temperature control > Exchanger

Pump stop delay

5 min

Delay for switching off the digital output: Exchanger pump (SEQ-B)

Pump-kick hour

15 h

Daily exercise run of the pump starts at 15h

Start delay exchanger

0 s


100% exchanger at start up

2 s



Graphical representation

Flowchart


"On" - indication of pump status


75% - indication of sequence output