Siemens SFP21/18, SFP71/18 User Manual

4

865

Elctromotoric Actuators

for small valves VVP47.., VXP47.., VMP47..

SFP21/18
SFP71/18

• SFP21/18 AC 230 V operating voltage, 2-position control signal

• SFP71/18 AC 24 V operating voltage, 2-position control signal

• 135 N positioning force

• Spring return

• Manual adjustment

• For direct mounting with union nut (no tools required)

• Integral 1.8 m connecting cable

• Auxiliary switch, type ASC2.1/18 (optional)

Use

The SFP21/18 and SFP71/18 actuators are used in conjunction with zone valves
VVP47.., VXP47.. and VMP47.., primarily in heating, ventilation, air conditioning and
refrigeration systems for water-based control of low-temperature hot water and cooling
water. The SFP.. actuators together with the 3-port valves VXP47.. are suitable for low
leakage change over applications.

Functions

The electric actuator requires an on/off controller (thermostat) to control the valve. If the
temperature of the medium deviates from the set-point, the controller output signal
causes the actuator to drive the valve open. When the temperature of the medium
reaches the set-point, the control signal is cut off and the valve closes again.

CA1N4865en

20.04.2011

Siemens Building Technologies

HVAC Products

2/6

Siemens Building Technologies Elctromotoric Actuators CA1N4865en
HVAC Products 20.04.2011

Type summary

Prod. no. Operating voltage Positioning time Control signal Connecting cable

SFP21/18 AC 230 V

SFP71/18 AC 24 V

10 s 2-position 1.8 m

Prod. no. Description Switching point Switching capacity Connecting cable

ASC2.1/18 Auxiliary switch

open/closed

At approx. 50% stroke AC 250 V / 3(2) A 1.8 m

Ordering

Actuators, valves and accessories are supplied separately. The actuator is supplied
with the AL50 ring.

See overview

Equipment combinations

Type code Valve type kvs PN class Data sheet

[m3/h]

VVP47.. 2-port valves

0.25...4.0

VXP47.. 3-port valves 0.25...4.0

VMP47.. 3-port valves with T-bypass 0.25...2.5

PN16 4847

Technical design / Mechanical design

The valve is opened electrically by the actuator and closed by spring force.
It incorporates a synchronous motor, a gear mechanism and a return spring.
The electric motor is overload-resistant and anti-locking, so that continuous operation is
possible. The maximum stroke is limited mechanically. The closing motion, by contrast,
includes an overrun for the gear mechanism. This protects the gear mechanism from
mechanical shock and increases service life.
The valve is connected by an 1.8 m cable, which is an integral part of the actuator.

Accessories

The optional auxiliary switch can be fitted to the actuator
with two screws.
It switches at a stroke of approx. 50 %.

• Valve actuator de-energized:

→ Auxiliary switch open

• Voltage applied to valve actuator:

→ Auxiliary switch closed (50 ... 100 % stroke)

• Manual adjuster locked into position

(approx. 90 % stroke):
→ Auxiliary switch closed

01468

See "Technical data" for further information on the auxiliary switch, page 5.

Accessories

Example:

Product number Stock number Designation Quantity

SFP71/18 SFP71/18 Electromotoric Actuators 2

ASC2.1/18 ASC2.1/18 Auxiliary Switch 1

Delivery

Rev. no.

ASC2.1/18
auxiliary switch