Glandless Pumps - THERMO-ECO-ENGINEERING úvod

Switchgears and Control Devices
Wilo-CRn and CR control devices
Series description Wilo-CRn, Wilo-CR
Stepless speed control
Stepless speed control must be regarded as the ideal solution to the
problem of achieving %100 harmonious matching of pump performance
to the actual operating states of the system.
Unfortunately, its particular inherent capability of reducing the speed
right down to a very low level – about 10–20% residual speed –
cannot be realised in practice in heating applications. Speed reductions
in the range below 60% residual speed and the resulting drop in
delivery head (delivery head as a quadratic function of speed) may
result in malfunctions and sometimes to a breakdown in water distribution.
In this case, the p measuring point must be installed in the
so-called index circuit of the system, i.e. line or consumer with the
greatest pressure losses. Extremely low speeds below 40% rated
motor speed can also lead to thermal and mechanical overloading of
the electric motors.
Control modes
The following control modes can be preselected for electronic pump
performance control when using the Comfort controller of the Wilo-
CR-Systems.
• For variable-delivery systems (e.g. heating systems with thermostatic
valves):
- Constant differential-pressure control (p-c)
- Variable differential-pressure control (p-v)
- Variable-delivery differential-pressure control (p-q)
- Temperature-superimposed differential-pressure control (p-T)
- Constant pressure control (p-c) for pressure boosting systems
- Constant flow rate control (Q-c)
• For constant-delivery systems
(e.g. cooling systems with heat exchangers):
- Differential temperature control (T)
- Process-temperature control (±T)
- Variable temperature control (T-v)
Control and signalling functions
The Wilo-CR-Systems have at their disposal an extensive range of
control inputs/outputs as standard equipment
for incorporation in external monitoring units to be provided by the
customer:
- Remote setpoint adjustment (0 – 10 V/10– 20 mA) can be preselected
- On- / Off control by external potential-free contact
- Freeze-up protection by external potential-free contact (applicable
only in conjunction with heating / air-conditioning) via digital input
- Low-water cut-out by external potential-free contact (only for pressure
boosting) via digital input
- Collective fault/run signal as potential-free switchover contacts
- “Mains – Emergency – Operation” service selector switch for maintenance
personnel
- Switchover to a second setpoint level
The following optional control inputs and outputs are available (only
in conjunction with accessory boards):
- Remote confirmation of collective fault signal (in connection with
DDC board)
- Switchover in manual control mode (in connection with DDC board)
- Individual run and fault signals for pumps and converters (in connection
with signal board)
- Manual / automatic-switchover (in conjunction with control board)
- Connection for repair switch with potential-free contact (in conjunction
with control board)
Type key CR control device (Example CR 1.1 2 WA)
CR
1,1
2
WA
User-friendly regulation technology
Maximum rated motor output P 2 of pump to
be controlled in kW
Number of pumps to be controlled
(1–6 pumps)
Device version
WA = wall-mounted installation IP 42
(IP 54 on request)
SG = floor model IP 42 (IP 54 on request)
SE = control-panel installation
Type Key CRn control device (Example CRn 1-2 TP WA)
CRn
1-2
TP, TK
WA
User-friendly regulation technology new
Number of connectable pumps:
1–2
3–4
5–6
Control mode:
T = Temperature
P = Sensor PT100
K = Sensor KTY
Device version
WA = wall-mounted installation IP 42
(IP 54 on request)
SE = control-panel installation
Heating, Air-conditioning,
Cooling
Potable water circulation
Solar thermal
Service/Accessories, Systems
Switchgears and Control Devices
Pump Management Systems
Wilo Catalogue A1 - Circulating pumps in glandless design
409