Master/Slave Assembly; Heat Reclaim Option (30Xa); Energy Management Module - Carrier 30XA Operation Instructions Manual

7.15 - Master/slave assembly

Two units can be linked to create the master/slave assembly.
The master unit can be controlled locally, remotely or by
network commands. Master/slave assembly must be validated
in order to start the master/slave chiller operation.
All control commands to the master/slave assembly (start/
stop, setpoint selection, heating/cooling operation, load
shedding,.etc.).are.handled.by.the.unit.which.is.configured.as.
the master. The commands are transmitted automatically to
the slave unit. If the master chiller is turned off while the
master/slave function is active, then the slave chiller will be
stopped. Under certain circumstances, the slave unit may be
started.first.to.balance.the.run.times.of.the.two.units.
In the event of a communication failure between the two
units, each unit will return to an autonomous operating mode
until the fault is cleared. If the master unit is stopped due to
an alarm, the slave unit is authorised to start.
NOTE: Master/slave assembly can be configured only by
Carrier service.

7.16 - Heat reclaim option (30XA)

Air-conditioning.system.consumes.a.significant.amount.of.
energy that leaves the system in the form of wasted heat.
Heat reclaim condenser water pump control enables to
capture the energy and convert it into a useful heat source
without decreasing the chiller plant capacity.
For.air-cooled.units.fitted.with.water.heat.reclaim.condenser,.
the option requires the installation of Reclaim SIOB board.
The heat reclaim mode can be controlled locally with the
Touch Pilot interface (RECLAIM – Reclaim mode),
remotely with the user contact or by Network command.
The heat reclaim function is active when the heat reclaim
entering water temperature is lower than the heat reclaim
setpoint. The difference between the heat reclaim entering
water temperature (RECLAIM menu) and the heat reclaim
setpoint (SETPOINT menu) determines the number of
circuits required to provide heat reclaim capacity.
Energy management option – board connections
Description Input/Output
Occupancy override control DI-01
Demand limit switch 2 DI-02
Customer interlock DI-03
Ice storage DI-04
Space temperature AI-01
Capacity limit control AI-10
Compressor A DO-01
Compressor B DO-02
Compressor C DO-03
Chiller shutdown DO-05
Chiller in alert DO-06
Unit capacity A0-01
30
Connector Type
J1 Digital input
J1 Digital input
J1 Digital input
J1 Digital input
J25 Analogue input
J9 Analogue input
J2 Digital output
J2 Digital output
J6 Digital output
J23 Digital output
J22 Digital output
J10 Analogue output
Depending on the control mode, the Heat Reclaim option
can be enabled as follows:
Mode Description
Local Use the Touch Pilot user interface to set "Heat Reclaim Select"
parameter to "yes" in the Reclaim menu (Main menu).
Remote Close the RECL_SW input (DI-02, Reclaim SIOB board).
Network Force the RECL_SW parameter to "yes" through the CCN bus
(RECLAIM table).
Units in Master/Slave assembly
When the unit is a Slave and operating in the Master/Slave
assembly, the option is active depending on conditions given
in the table below:
Reclaim Local mode (Heat
mode Reclaim Select = yes)
no no
yes yes/no
yes yes
yes yes/no
The heat reclaim function can be deactivated manually or
automatically when the heat reclaim entering water temperature
is higher than the heat reclaim setpoint, plus half of the heat
reclaim deadband. In the deadband the heat reclaim function
is still active.
Changeover procedure from cooling to heat reclaim mode:
1) Start-up of the condenser pump.
2) Verification.of.the.condenser.flow.switch.control.
contact. If this remains open after one minute of the
condenser pump operation, the circuit remains in
cooling mode and an alarm will be activated.
3) As soon as delta between saturated condensing
temperature and saturated suction temperature
reaches 10°C, the pump-down sequence is activated.
4) Pump down. Opening of the water condenser water
inlet valve and closing of the air condenser air valve.
5) The heat reclaim function starts after about three minutes.

7.17 - Energy management module

The energy management module enables to control the level
of energy consumption, providing users with information
such as current unit status, compressors operating status, etc.
This option requires the installation of an additional SIOB
board.
Remarks
If the contact is closed in Remote mode, the unit goes into the occupied mode
If the contact is closed, the second capacity limit switch is active
Permits immediate unit shutdown (Remote mode only)
If the contact is closed, the unit enters the ice storage mode
Active setpoint reset via space temperature control
Active setpoint reset via unit capacity control (4-20 mA)
Output active if compressor A is operating
Output active if compressor B is operating
Output active if compressor C is operating
Output active (relay output) when the unit has completely stopped due to an alarm
Output active (relay output) when the alert has been tripped
0 to10 VDC output
Remote mode Network mode
(RECL_SW) (RECL_SEL CCN bus)
open no
closed yes/no
open yes/no
open yes