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8.5.1 - Variable speed pumps control
30RBS chillers and 30RQS
heat pumps may be fitted with
one or two variable speed pumps.
Variable speed pumps give the possibility of saving the
pumping energy cost, providing precise water flow control
and improving the overall performance of the system. The
frequency inverter continuously regulates the flow rate to
minimise the pump power consumption at full load and
part load.
Water flow management methods are as follows:
1) Fixed speed control (the control ensures a constant
pump speed based on compressor capacity).
2) Water flow control based on constant water delta
pressure (the control continuously acts on the pump
speed to ensure a constant delta pressure).
3) Water flow control based on constant delta T on the
water exchanger.
IMPORTANT:
Pump speed configuration can be
performed only by Carrier service.
8.5.2 - Pumps configuration
The control can command internal fixed speed or variable
speed pumps as well as customer pumps. Variable speed
pumps may also be configured as fixed speed pumps (see
also section 8.5.1).
Basic pump configuration can be performed via the
Configuration menu (PUMPCONF – Pump
Configuration). Only logged-in users can access the menu.
The unit must be stopped.
To set pumps sequence
1. Navigate to the Configuration menu.
2. Select
Pump Configuration
(PUMPCONF).
3. Set
Water Pumps Sequence
[pump_seq].
Water Pumps Sequence [pump_seq]
0
No Pump
1
One Pump Only
2
Two Pumps Auto
3
Pump#1 Manual
4
Pump#2 Manual
8.5.3 - Automatic pump selection
If two pumps are controlled and the reversing function has
been selected (PUMPCONF – Pump Configuration), the
control balances the pump run time to match the
configured pump changeover delay. If this delay has
elapsed, the pump reversing function is activated.
To set pump automatic rotation delay
1. Navigate to the Configuration menu.
2. Select
Pump Configuration
(PUMPCONF).
3. Set
Pump Rotation Delay
[pump_del].
Pump Rotation Delay [pump_del]
24 to 3000h
48h
8.5.4 - Customer pumps configuration
Units fitted with external pumps may have only fixed
speed pumps available. Customer pumps may be
configured as follows:
Pump available
Pumps sequence (PUMPCONF)
No pump
0 (no pump)
One single speed pump
1 (one pump only)
Two single speed pumps
2 (two pumps auto)
3 (pump#1 manual)
4 (pump#2 manual)
Units with customer pumps are fitted with the flow switch,
allowing for the water flow control. For more information
about actuators, see
Water flow switch
in section 4.7.
8.5.5 - Pumps protection
The control provides the option to automatically start the
pump each day at 14:00 for 2 seconds when the unit is off.
If the unit is fitted with two pumps, the first pump is started
on even days and the second pump is started on odd days.
Starting the pump periodically for a few seconds extends
the lifetime of the pump bearings and the tightness of the
pump seal.
Periodical pump quick start can be selected via the
Configuration menu (PUMPCONF – Pump
Configuration).
To set periodical pump quick start
1. Navigate to the Configuration menu.
2. Select
Pump Configuration
(PUMPCONF).
3. Set
Pump Sticking Protection
[pump_per].
Pump Sticking Protection [pump_per]
No/Yes
Yes
8.6 - Hydronic kit option
The hydronic kit option allows for continuous monitoring
of the water flow rate (PUMPSTAT – Pump Status).
The hydronic kit provides the option to measure the
following parameters:
•
Inlet and outlet water pressure.
•
Water exchanger flow rate.
The water flow rate is based on the pressure difference
between the inlet and outlet pressures and the pressure
drop curves.
Hydronic kit option with variable speed pumps
For units with variable speed pumps, this option allows for
the automatic adjustment of the pump speed necessary to
maintain the correct water flow rate. Water flow control
can be based on compressor usage, constant delta pressure
or constant temperature difference. For more information
on variable speed pumps control, see also section 8.5.1.
