8
Connections available at the user terminal block may vary
depending on the selected options.
3.8.2 - Volt-free on/off contact
If the unit operates in Remote mode, the on/off contacts is
as follows:
Cooling
open closed
Legend:
1. O: Unit is stopped
2. Cooling: Unit is allowed to start in Cooling
3.8.3 - Volt-free setpoint selection contact
This dry contact input is used to switch between setpoints.
It is active only when the control is in Remote mode.
Cooling
Setpoint 1 Setpoint 2
Setpoint selection contact open closed
3.8.4 - Volt-free demand limit selection contact
Up to two dry contacts can be used to limit unit capacity.
Note that the second contact is available for units with the
energy management module.
Capacity limitation with two contacts is as follows:
100% Limit 1 Limit 2 Limit 3
open closed open closed
open open closed closed
The limits are dened in the SETPOINT menu.
3.8.1 - Terminal block connections
Some contacts can be accessed only when the unit
operates in Remote mode.
The following table summarises the connections at the
user terminal block.
type
Channel/
Connector
Remarks
On/O switch SIOB, circuit A DI-01 J1 Used for the unit on/o control if the unit is in Remote mode
Second setpoint switch SIOB, circuit A DI-02 J1 The contact is taken into consideration if the unit is in Remote mode
Demand limit switch 1 SIOB, circuit A DI-03 J1 Used to control demand limit. See section 6.5
Alarm relay SIOB, circuit A DO-05 J23 Indicates alarms
Running relay SIOB, circuit A DO-06 J22 Indicates if the unit is ready to start or operating
Optional
Occupancy override switch NRCP2, EMM DI Ch 08 Used to switch between occupied (closed contact) and unoccupied
mode (open contact)
Capacity limit switch input 2 NRCP2, EMM DI Ch 09 Used to control demand limit
Customer interlock NRCP2, EMM DI Ch 10 Used for the customer safety loops (if the contact is closed, the
chiller is stopped)
Ice done contact NRCP2, EMM DI Ch 11a Used to control the setpoint according to the occupancy schedule
To Next Page
Loading...
