Danfoss PM2 P Fact sheet

Danfoss PM2+P Domestic Hot Water Controller

Proportional flow controller with integrated differential pressure controller

Unique control technology with esaveTM function, which saves energy and spares the environment.

Application

The Danfoss PM2+P controller is used to control the domestic hot water temperature in combination with a plate heat exchanger in the Danfoss Redan product series AkvaVita II.

Capacity

The capacity of the controller fully covers the domestic hot water need of a standard dwelling.

Function, esaveTM

The controller is pressure controlled. It is designed with esaveTM function, a pressure control feature, which ensures that district heating water is led to the instantaneous water heater only when hot water is tapped and that the flow of district heating water is shut off, when the tapping of domestic hot water ends.

The PM2+P controller is supplied with a built in differential pressure controller, which ensures a constant pressure drop over the control valve. This ensures a very stable domestic hot water temperature, which is independent of variations in differential pressure.

Standby losses

Due to the esaveTM energy saving functionality of the controller, standby losses are

avoided. When the tapping of domestic

hot water ends, the controller immediately shuts off the flow of district heating water into the heat exchanger. This means that energy (district heating) is needed only, when hot water is tapped.

Lime scale deposits in the heat exchanger

Normally no lime scale will occur when the heat exchanger is used in combination with a PM2+P controller. When hot water is not consumed, the district heating flow is also shut off and the temperature in the secondary side of the heat exchanger does notexceedthetemperature(approx.55°C), at which lime scale is deposited.

Materials

The controller is made of materials, which have been approved for fresh water purposes.

The controller housing is made of dezinci- fication-free brass. The spindle is made of stainless steel and the sensor of copper. All O-rings and the membrane are made of EPDM rubber.

Options

If the domestic water installation is made with circulation, it is recommended to establish a bypass above the district heating part of the PM2+P controller.

By means of a return flow thermostat and the connecting capillary tubes separate control of the circulation and domestic hot water temperature is made possible.

Mounting

The controller must be installed in a way that allows the medium to flow in the direction as shown on the drawing on the back page. The insertion position of the sensor is optional and it is recommended that the sensor is placed firmly into the hot water outlet connecting piece of the heat exchanger.

Features and Benefits

•Suitableforlowtemperatureareas

•Perfectcontrolofdomestichotwater temperature under all conditions

•WithesaveTM function

•Nostandbylosses,-lowenergyconsump- tion

•Maximumcomfort

•Controlrange45-65°C

•VAapproved

VL.GE.O1.02 © Danfoss 11/2010

Danfoss PM2+P with esaveTM function

Principle:

When tapping starts, cold water flows into the secondary side of the controller (1), passes the secondary side cone (2), leaves the controller (3) and enters the heat exchanger. The pressure drop generated during tapping of domestic hot water is transferred to the diaphragm(4)whichtransferstheforcetothespring.Thiscausesthe main spindle (5) to move to the right, which opens the primary side cone (6).The opening results in primary flow entering from the heat exchanger into the controller (7), where it passes the primary side cone (6) of the integrated differential pressure controller (8) and leaves the controller (9).

KV	VV	FV	FV
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The temperature sensor mounted on the secondary hot water side is sensing the temperature. If the temperature is deviating from the setting temperature the thermostatic element will move (open/close) primary side cone (6) until desired temperature is reached. By rotating the handle for temperature setting (10), the domestic hot water temperature can be adjusted.The setting range of the controller is 45°C to 65°C.

When there is no demand for domestic hot water, the heat exchanger is always cold. A bypass function ensures that the supply pipe for the water heater is always kept warm, so that hot water is produced immediately, when tapping starts. The no-load temperature is set on the bypass thermostat (13) and is independent on the set domestic hot water temperature.

Domestic hot water circulation connection (11) and idle controller connection (12) are placed directly on the controller. If the domestic water installation is made with circulation, the circulation pipe is connected to the connecting piece of the controller (11). The bypass thermostat is connected to the controller (12). The circulation water temperature is controlled individually by the bypass thermostat (13), independently of the set domestic hot water temperature.The built in differential pressure controller (8) ensures optimum operation of the domestic hot water controller under all operating conditions.

Main data for the PM2+P controller:

Dimensioned sketches:

Dimensions, weight
Size of packaging:	H76 xW61 x L206 mm.
Weight:	1.3 kg. (incl. of packaging).
Materials
Controller housings:	Dezincification-free brass
Piston:	MPPE Noryl
Spindle /guide:	Stainless, acid-resisting steel
O-rings / membrane:	EPDM
Sensor:	Copper
Technical data
Nominel diameter		DN 15
Version	2,4		3,0
Min. flow rate, primary	70 l/h		100 l/h
Max. flow rate, primary	1000 l/h		1200 l/h
Min. flow rate, secondary		120 l/h
Max. flow rate, secondary		1400 l/h
Nominal pressure, primary		PN 16
Max. Δp, primary		6 bar
Max. temperature, primary		120°C
Setting range		45 - 65°C
Medium	DH water/glycolic water 30%

Variants:

Angular with union nut connection

Angular with O-ring connection

Danfoss Redan A/S · District Energy Division · Omega 7 · Søften · DK-8283 Hinnerup

Tel.: [phone] · Fax: [phone] · [e-mail] · www.redan.danfoss.dk

VL.GE.O1.02 © Danfoss 11/2010

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