Glanded Pumps - THERMO-ECO-ENGINEERING úvod

Planning Guide
Principle of operation
Auto speed control applies to the main (base-load) pump head.
With full stabilisation of this aggregate, i.e. with the nominal pump
speed achieved and the start of the peak load requirement, the peak
load aggregate switches in at a fixed speed (nominal speed), whilst
the power of the controlled base load pump is directly reduced and
adjusted to the load point. Pressure surges resulting from starting
and stopping the trailing pumps are relatively minor and in practice
have no appreciable effect. In parallel operation the constant speed
peak load aggregate and the controllable base load aggregate are
added, based on delivery flow, which in this operating situation readjusts
for the respective peak load requirement.
The switch-point for adding the peak-load head is determined by means
of a unit-integrated electronic assessment logic.
Note:
Peak-load control functions of Wilo auto control systems are only
possible on head- or differential temperature-sensitive control
modes.
Further information on pump regulation is contained in the catalogue
section “Switching devices and control systems”.
Twin-head pump switching
There are two operating modes for the operation of twin-head
pumps:
- Standby switching of one pump with the other is on duty in singlepump
operation.
- Peak load switching with parallel operation of both pumps, which are
also combined from a control option on the respective operating
pump.
Operating modes
Standby operation Peak load operation
No. I or No. II pump in operation Both pumps operating
Duty pump uncontrolled
Pump I
Investment costs:
Operating costs:
Wilo Catalogue A2 - Glanded pumps
Pump II
lower
high
Pump I + II
higher
low
Operating pump controlled by means of Wilo control system
Pump I
Investment costs
(Including control):
Operating costs:
Pump II
higher
higher
Pump I + II
lower
low
Operating Functions
Wilo switching devices feature the following operating functions:
A standby switching, fault-sensitive or time-sensitive operational
changeover Pump I Pump II.
B Peak-load operation for load- or time-sensitive automatic load
adjustment through ON / OFF control of the trailing pump.
C Infinitely-variable speed control of the leading pump for load- or
time-sensitive automatic power adjustment when the trailing
pump it switched on for infinitely-variable peak-load service.
Switchgear Switch function
A B C
SD Series (Standby / Cut-in) • • –
S2R 3D (Standby / Cut-in) • • –
CR System (stepless) • • •
Series S2R 3D / SD
Changeover panels for auto-control of operating and standby pumps
of dual sets. Automatic fault-actuated changeover from operating to
standby pump. Automatic time-controlled routine duty changeover
of operating and standby pumps.
Additional peak load switching through series standard connection
option for the 2nd pump.
Short-term parallel running is integrated into the changeover
sequence to avoid the occurrence of valve noise during uncontrolled
changeover.
Version in ISO housing, Protection Class: IP 41. Potential-free contact
for collective fault signal.
Connection options to three-phase current 400 V, 50 Hz, or threephase
230 V, 50 Hz.
Non-standard voltages and frequencies on request.
Technical Data
Switchgear type Motor power
[kW]
S2R 3D 0.37-3
SD 5.5 4-5.5
SD 9 7.5- 9
SD 18.5 11-18.5
SD 30 22-30
SD 37 37
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Planning Guide
Energy-saving pumps
Standard pumps
Special pumps
Pump management