Wilo Varios PICO-STG User manual

4 235 775-Ed.02 / 2021-03
Willo-Varios PICO-STG
Pioneering for You
en Installation and operating instructions

Fig. 1:
1
2
3
4
5
6
13
14
15
9
10
12 11
8
7
6

Fig. 2:
Fig. 3:
a
b
Fig. 4:
Fig. 5a:
Fig. 5b:
1
2
PE NL

Fig. 5c:
Fig. 5d:
Fig. 5e:
Fig. 5f:
Fig. 6:

Installation and operating instructions Wilo-Varios PICO-STG 7
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1General
About these
instructions
These installation and operating instructions are an
integral part of the product. Read these instructions
before commencing work and keep them in an accessi-
ble place at all times.
Strict adherence to these instructions is a requirement
for intended use and correctly operating the product. All
specifications and markings on the product must be
observed.
The language of the original operating instructions is
German. All other languages of these instructions are
translations of the original operating instructions.
2Safety
This section contains basic information which must be
adhered to during installation, operation and mainte-
nance. Additionally, the instructions and safety instruc-
tions in the other sections must be followed.
Failure to follow the installation and operating instruc-
tions will result in the risk of injury to persons and dam-
age to the environment and the product. This will result
in the loss of any claims for damages.
Failure to follow the instructions will, for example, result
in the following risks:
• Injury to persons from electrical, mechanical and bac-
teriological factors as well as electromagnetic fields
• Environmental damage from leakage of hazardous
substances
• Property damage
• Failure of important functions of the product
Identification of
safety instructions
These installation and operating instructions set out
safety instructions for preventing personal injury and
damage to property, which are displayed in different
ways:
• Safety instructions relating to personal injury start
with a signal word and are preceded by a corre-
sponding symbol.

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• Safety instructions relating to property damage start
with a signal word and are displayed
without a symbol.
Signal words DANGER!
Failure to observe safety instructions will result in seri-
ous injury or death!
WARNING!
Failure to follow instructions can lead to (serious) injury!
CAUTION!
Failure to follow instructions can lead to property dam-
age and possible total loss.
NOTICE
Useful information on handling the product
Symbols These instructions use the following symbols:
Personnel
qualifications
Personnel must:
• Be instructed about locally applicable regulations
governing accident prevention.
• Have read and understood the installation and oper-
ating instructions.
Personnel must have the following qualifications.
• Electrical work must be carried out by a qualified elec-
trician (in accordance with EN 50110-1).
Danger due to electrical voltage
General danger symbol
Warning of hot surfaces/fluids
Warning of magnetic fields
Notices

Installation and operating instructions Wilo-Varios PICO-STG 9
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• Installation/dismantling must be carried out by a
qualified technician who is trained in the use of the
necessary tools and fixation materials.
• The product must be operated by persons who are
instructed on how the complete system functions.
Definition of “qualified electrician”
A qualified electrician is a person with appropriate techni
-
cal training, knowledge and experience who can identify
and prevent electrical hazards.
Electrical work • Electrical work must be performed by a qualified elec-
trician.
• Nationally applicable guidelines, standards and regu-
lations as well as specifications issued by the local
energy supply companies for connection to the local
power supply system must be observed.
• Before commencing work, disconnect the product
from the mains and safeguard it from being switched
on again.
• The connection must be protected by means of a
residual-current device (RCD).
• The product must be earthed.
• Have defective cables replaced immediately by a
qualified electrician.
• Never open the control module and never remove
control elements.
Operator
responsibilities
• Have all work carried out by qualified personnel only.
• Ensure on-site guard against hot components and
electrical hazards.
• Have defective gaskets and connection pipes
replaced.
This device can be used by children from 8 years of age as
well as by people with reduced physical, sensory or mental
capacities or lack of experience and knowledge if they are
supervised or instructed in the safe use of the device and
they understand the dangers that can occur. Children are
not allowed to play with the device. Cleaning and user
maintenance is not allowed to be carried out by children
without supervision.

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3 Product description and function
Overview Wilo-Varios PICO-STG (Fig. 1)
1 Pump housing with screwed connections
2 Glandless motor
3 Condensate drain openings
(4x around circumference)
4Housing screws
5 Control module
6iPWM signal cable connection
7 Rating plate
8 Operating buttons for pump adjustment
9 Fault signal LED
10 Display of control mode
11 Display of iPWM signal type
12 Display of set pump curve (I, II, III)
13 Mains connection: 3-pin plug connection
14 Wilo-Connector
15 Connection cable: 3-pin pump plug and
Wilo-Connector connection
Function High-efficiency circulator for hot-water heating sys-
tems with integrated differential pressure control. Con-
trol mode and delivery head (differential pressure) are
adjustable. The differential pressure is controlled via the
pump speed.
Type key
Example: Wilo-Varios PICO-STG 25/1-7-130
Varios PICO High-efficiency circulator
STG Compatible with heating, solar and geothermal application
25 Screwed connection DN 25 (Rp 1)
1-7 1 = minimum delivery head in m (adjustable down to 0.5 m)
7 = maximum delivery head in m at Q = 0 m³/h
130 Port-to-port length: 130 mm or 180 mm

Installation and operating instructions Wilo-Varios PICO-STG 11
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Technical data
Indicator lights
(LEDs)
• Display of selected control mode Δp-v, Δp-c,
constant speed and external speed control
• Display of selected pump curve (I, II, III) or iPWM signal
type (iPWM GT, iPWM ST) within the control mode.
• LED indicator combinations during pump venting
function, manual restart and LED coding within the
sync function.
•Signal display
• LED lights up green during normal operation.
• LED flashes red or green or lights up permanently
red in the case of a fault signal.
• LED lights up red in the event of incorrect LED cod-
ing after ending the sync function.
Connection voltage 1 ~ 230 V ± 10%, 50/60 Hz
Protection class IP See rating plate (7)
Energy efficiency index EEI See rating plate (7)
Fluid temperatures at max. ambient
temperature +40 °C -20 °C to +95 °C (Heating/GT) -10 °C to +110 °C (ST)
Fluid temperatures at max. ambient
temperature +70 °C +70 °C
Permitted ambient temperature -10 °C to +70 °C
Max. operating pressure 10 bar (1000 kPa)
Minimum inlet pressure
at +95 °C/+110 °C 0.3 bar/1.0 bar (30 kPa/100 kPa)

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Operating buttons
Upper operating button
Press
•Select control mode.
• Activate the pump venting function (press and hold).
• Select the LED during the sync function.
Lower operating button
Press
• Selection of pump curve (I, II, III) or iPWM signal
(iPWM GT, iPWM ST) within the control mode.
• Activate manual restart (press and hold).
• Activate or deactivate selected LED during the sync
function.
3.1 Control modes and functions
Variable
differential
pressure Δp-v
(I, II, III)
Recommended for two-pipe heating systems with radi-
ators to reduce the flow noise at thermostatic valves.
The pump reduces the delivery head to half in the case of
decreasing volume flow in the pipe network.
Electrical energy saving by adjusting the delivery head to
the volume flow requirement and lower flow rates.
There are three pre-defined pump curves (I, II, III) to
choose from.
II
III
I
H/m
Q/m³/h
NOTICE
Factory setting: Δp-v, pump curve II

Installation and operating instructions Wilo-Varios PICO-STG 13
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Constant
differential
pressure Δp-c
(I, II, III)
Recommended for underfloor heating.
Or for large-sized pipes, applications without a variable
pipe network curve (e.g. storage charge pumps) or sin-
gle-pipe heating systems with radiators.
The controls keep the set delivery head constant, inde-
pendent of the delivered volume flow.
There are three pre-defined pump curves (I, II, III) to
choose from.
Constant speed
(I, II, III)
Recommended for systems with fixed system resistance
requiring a constant volume flow.
The pump runs uncontrolled in three prescribed fixed
speed stages (I, II, III).
External control via
a iPWM signal
The required setpoint/actual value comparison for con-
trol is performed by an external controller.
A PWM signal (pulse-width modulation) is fed as a cor-
recting variable to the pump.
The iPWM signal generator gives the pump a periodic
sequence of impulses (the duty cycle) in accordance
with DIN IEC 60469-1.
III
I
II
H/m
Q/m³/h
I
III
II
H/m
Q/m³/h
55 (45)%
45 (55)%
5 (95)%
65 (35)%
35 (65)%
75 (25)%
85 (15)%
15 (85)%
25 (75)%
H/m
Q/m³/h
% iPWM GT (% iPWM ST)

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iPWM GT mode (Heating and geothermal):
In iPWM GT mode, the pump speed is controlled accord-
ing to the iPWM input signal.
Behaviour in the event of a cable break:
If the signal cable is separated from the pump, e.g. due
to a cable break, the pump accelerates to maximum
speed.
iPWM signal input [%]
< 5: Pump runs at maximum speed
5-85: The speed of the pump decreases linearly
from nmax to nmin
85-93: Pump runs at minimum speed (operation)
85-88: Pump runs at minimum speed (starting)
93-100: Pump stops (standby)
iPWM ST mode (Solar):
In iPWM ST mode, the pump speed is controlled accord-
ing to the iPWM input signal.
Behaviour in the event of a cable break:
If the signal cable is separated from the pump, e.g. due
to a cable break, the pump stops.
iPWM signal input [%]
0-7: Pump stops (standby)
7-15: Pump runs at minimum speed (operation)
12-15: Pump runs at minimum speed (starting)
15-95: The speed of the pump increases linearly
from nmin to nmax
> 95: Pump runs at maximum speed
Venting
The pump venting function is activated by pressing and
holding the upper operating button and automatically
vents the pump.
The heating system is not vented.
max
n
¹/min
min
058588
93 100 PWM
%
max
min
07121595 100 PWM
%
n
¹/min

Installation and operating instructions Wilo-Varios PICO-STG 15
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Manual restart
A manual restart is activated by pressing and holding
the lower operating button and unblocks the pump as
required (e.g. after long idle time in summer).
Sync function
The sync function is activated by simultaneously press-
ing the upper and lower operating buttons.
The synchronisation function can be activated if the
pump curves of a pump to be replaced need to be repro-
duced.
The pump curves are reproduced by reprogramming the
pump using straightforward LED coding. Information on
suitable replacement pumps and LED coding is available
in the Wilo replacement guide or in the Wilo Assistant
app.
4 Intended use
The high-efficiency circulators in the Wilo-Varios PICO-
STG series are exclusively designed for circulating fluids
in hot-water heating systems and similar systems with
constantly changing volume flows and/or in the primary
circuits of solar and geothermal systems.
Permitted fluids:
• Heating water according to VDI 2035
(CH: SWKI BT 102-01).
• Water-glycol mixtures* with a maximum of 50 % glycol.
* Glycol has a higher viscosity than water. If admixtures
of glycol are used, the pumping data of the pump must
be corrected to match the mixing ratio.
Intended use includes observing these instructions and
the specifications and markings on the pump.
NOTICE
Only introduce ready-to-use mixtures to the
system. The pump must not be used to mix fluid
in the system.

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Misuse Any use beyond the intended use is considered misuse
and will void any warranty claims.
5 Transportation and storage
Scope of delivery • High-efficiency circulator
•2gaskets
• Mains connection cable with 3-pin pump plug and
Wilo-Connector connection
• Wilo-Connector
• Installation and operating instructions
Transport
inspection
Immediately check for transportation damage and com-
pleteness upon delivery, and lodge any complaints
immediately.
Transport and
storage conditions
Protect against moisture, frost and mechanical loads.
Permissible temperature range: -10 °C to +50 °C.
WARNING!
Danger of injury or material damage from improper
use!
• Never use non-specified fluids.
• Never allow unauthorised persons to carry out work.
• Never operate the pump beyond the specified limits
of use.
• Never carry out unauthorised conversions.
• Use authorised accessories only.
• Never operate with phase angle control.

Installation and operating instructions Wilo-Varios PICO-STG 17
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6 Installation and electrical connection
6.1 Installation
May only be installed by qualified technicians.
Preparation • Choose an installation point that is as easily accessible
as possible.
• Observe the pump’s permitted installation
position (Fig. 2) and rotate the motor head (2+5) if
necessary.
• Install shut-off devices upstream and downstream of
the pump to facilitate pump replacement.
WARNING!
Risk of burns from hot surfaces!
Pump housing (1) and glandless motor (2) may become
hot and cause burns if touched.
• During operation, only touch the control module (5).
• Allow the pump to cool down before commencing
any work.
WARNING!
Risk of scalding from hot fluids!
Hot fluids can cause scalding. Before installing or
removing the pump, or loosening the housing
screws (4), note the following:
• Allow the heating system to cool down completely.
• Close shut-off devices or drain the heating system.
CAUTION!
An incorrect installation position may damage the
pump.
• Select the installation point according to the permit-
ted installation position (Fig. 2).
• The motor must always be installed horizontally.
• The electrical connection must never face upwards.

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• Align the upper shut-off device laterally.
• When installing in the feed of open systems, the
safety supply must branch off upstream of the pump
(EN 12828).
• Complete all welding and brazing work.
• Flush the pipe system.
Rotating the
motor head
Rotate the motor head (2+5) before installing and con-
necting the pump.
• If necessary, remove the thermal insulation shell.
• Hold the motor head (2+5) and unscrew the 4 housing
screws (4).
• Carefully rotate the motor head (2+5).
• Observe the permitted installation position (Fig. 2)
and the direction arrow on the pump housing (1).
• Tighten (4-7.5 Nm) the 4 housing screws (4).
CAUTION!
Leaking water may damage the control module.
• Align the upper shut-off device such that leaking
water cannot drip onto the control module (5).
WARNING!
Risk of fatal injury from magnetic field!
Risk of fatal injury for people with medical implants due
to permanent magnets installed in the pump.
• Never remove the rotor.
1
2
45
CAUTION!
Damage to the inner gasket causes leakage.
• Carefully rotate the motor head (2+5) without
removing it from the pump housing (1).

Installation and operating instructions Wilo-Varios PICO-STG 19
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Installing the pump Observe the following points when installing the pump:
• Note the direction arrow on the pump housing (1).
• Install glandless motor (2) horizontally, without
mechanical tension.
• Place gaskets in the screwed connections.
• Screw on threaded pipe unions.
• Use an open-end wrench to secure the pump against
twisting and screw tightly to piping.
• Re-mount the thermal insulation shell if required.
6.2 Electrical connection
The electrical connection may only be carried out by a
qualified electrician.
1
2
3
CAUTION!
Insufficient heat dissipation and condensation water
may damage the control module and the glandless
motor.
• Do not thermally insulate the glandless motor (2).
• Ensure all condensate drain openings (3) are kept
free.
DANGER!
Risk of fatal injury from electrical voltage!
Immediate risk of fatal injury if live components are
touched.
• Before commencing work, switch off the power sup-
ply and secure it from being switched on again.
• Never open the control module (6) and never remove
control elements.

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Preparation • The current type and voltage must agree with the
specifications on the rating plate (7).
• Maximum back-up fuse: 10 A, slow-blow.
• Only operate the pump with sinusoidal AC voltage.
• Note the switching frequency:
- On/off switching operations via mains voltage
≤ 100/24 h.
- ≤ 20/h for a switching frequency of 1 min.
between switching on/off via mains voltage.
• The electrical connection must be made via a fixed
connecting cable equipped with a connector device or
an all-pole switch with a contact opening width of at
least 3 mm (VDE 0700/Part 1).
• Use a connecting cable with sufficient outer diameter
(e.g. H05VV-F3G1.5) to protect against leaking water and
to ensure strain relief on the threaded cable connection.
• Use a heat-resistant connecting cable where fluid
temperatures exceed 90 °C.
• Ensure that the connecting cable does not make con-
tact with either the pipes or the pump.
Pump cable
connection
Installing the supplied mains connection cable (15)
• Press down the locking button of the 3-pin pump
plug and connect the plug to the plug connection (13)
of the control module until it snaps into place (Fig. 4).
CAUTION!
Pulsed mains voltage can cause damage to electronic
components.
• Never operate the pump with phase angle control.
• When switching the pump on or off using an external
control unit, deactivate any voltage pulse (e.g. phase
angle control).
• For applications where it is not clear whether the
pump is operated with pulsed voltage, get the con-
trol/system manufacturer to confirm that the pump
is operated with sinusoidal AC voltage.
• Switching the pump on/off via triacs/solid-state
relays must be examined on a case-by-case basis.

Installation and operating instructions Wilo-Varios PICO-STG 21
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Wilo-Connector
connection
Installing Wilo-Connector
• Disconnect the connecting cable from the power
supply.
• Observe terminal assignment (; (PE), N, L).
• Connect and install the Wilo-Connector
(Fig. 5a to 5e).
Connecting the pump
• Earth the pump.
• Connect Wilo-Connector (14) to the connection
cable (15) until it snaps into place (Fig. 5f).
Removing the Wilo-Connector
• Disconnect the connecting cable from the power supply.
• Remove the Wilo-Connector using a suitable screw-
driver (Fig. 6).
Connection to an
existing device
The pump can be directly connected to an existing pump
cable with a 3-pin plug (e.g. Molex) when being replaced
(Fig. 3, item a).
• Disconnect the connecting cable from the power
supply.
• Press down the locking button of the installed plug
and remove the plug from the control module.
• Observe the terminal assignment (PE, N, L).
• Connect the existing device plug to the plug
connection (13) of the control module.
iPWM connection Connecting the iPWM signal cable (accessories)
• Connect the signal cable to the PWM connection (6)
until it snaps into place.
• Cable assignment:
1 brown: PWM input (from controller)
2 blue or grey: Signal earth (GND)
3 black: PWM output (from the pump)
•Signal properties:
- Signal frequency: 100 Hz – 5000 Hz
(1000 Hz nominal)
- Signal amplitude: min. 3.6 V at 3 mA to 24 V
for 7.5 mA, absorbed by the pump interface.

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- Signal polarity: none
7 Commissioning
Commissioning only by qualified technicians.
7.1 Venting
• Fill and vent the system correctly.
If the pump does not vent automatically:
• Activate the pump venting function via the upper
operating button: press and hold for 5 seconds, then
release.
The pump venting function is initiated and
lasts 10 minutes.
The upper and lower LED rows flash in turn.
• Press the upper operating button quickly 2x to cancel.
7.2 Setting the control mode
Select control mode Pressing the upper operating button:
LED indicates the set control mode
• 1st pressing of button: set control mode Δp-v.
CAUTION!
The connection of mains voltage (AC) will destroy the
PWM input and cause serious damage to the product.
• At the PWM input the maximum voltage is 24 V
pulsed input voltage.
NOTICE
After venting, the LED display shows the previ-
ously set values of the pump.