Danfoss EIM 336 Data sheet

Data Sheet

Superheat controller Type EIM 336

For stepper motor valves

The EIM 336 is a superheat controller that can be used to control the opening degree of a valve based on the superheat of the evaporator. This is applicable in applications such as air conditioning, heat pumps and refrigeration.

An alternative option is to use the controller in manual mode via modbus communication and use it as a valve driver by setting the valve opening degree manually.

Benets

• The evaporator is charged optimally even when there are large variations in load and suction pressure.

• The superheat control can save energy by ensuring optimum utilization of the evaporator.

• The superheat is controlled to the lowest stable value.

• It controls EEV in microsteps providing a smooth superheat curve and less noise.

Features

• Minimum Stable Superheat search regulation (MSS).

• Maximum Operating Pressure function (MOP).

• Defrost.

• Compressor protection functions.

• Evaporator temperature (Te) control for dehumidifying.

• Valve driver via Modbus Communication.

• Loss Of Charge indication (LOC).

AI219486429676en-000301

Pressure transducer

Temperature sensor

Programming key / display

Electric Expansion valve

DST P110, AKS 32R, NSK BExx

AKS 21, AKS 11

MYK - EIM interfacer

ETS6

Superheat controller, Type EIM 336

1 Portfolio overview

Table 1: Related products

Superheat controller, Type EIM 336

2 Functions

2.1 Acronyms and abbreviations

LOC Loss of charge indication SH Superheat MOP Maximum operating pressure MSS Minimum stable superheat Te Saturated suction temperature Pe (Po) Evaporator pressure S2 Evaporator refrigerant outlet temperature S4 Evaporator medium outlet temperature OD Opening degree PNU Parameter number - is equivalent to the modbus register no. (modbus adress + 1)

2.2 Functions

Minimum Stable Superheat (MSS)

The controller will search for the minimum stable superheat between an upper and lower boundary set by the user. If the superheat has been stable for a period of 6 minutes, the superheat reference is decreased. If the superheat becomes unstable, the reference is raised again. This process continues as long as the superheat is within the bounds set by the user. The purpose of this is to search for the lowest possible superheat that can be obtained while still maintaining a stable system. The superheat reference can also be xed, in which case this function is disabled.

Maximum Operating Pressure (MOP)

In order to reduce the strain on the compressor, a maximum operating pressure can be set. If the pressure comes above this limit the controller will control the valve to provide a lower pressure instead of a low superheat. The limit for this function is usually a xed pressure, but it is possible to oset the limit temporarily.

Evaporator temperature (Te) control for de-humidifying

A function is provided to control on the evaporator temperature instead of the superheat. This can be used to dehumidify the air owing through the evaporator. By lowering the evaporators surface temperature, the water vapor in the air is condensed.

Superheat close

When the superheat is below a set minimum value, the valve will close faster in order to protect the compressor from the risk of getting liquid in the suction line.

Manual control

The valve can be controlled manually by setting the desired opening degree via modbus.

Start/stop of regulation

The start or stop of the regulation can be controlled by setting the software main switch, which is accessible via modbus. It is however also possible to use a digital input from an external Regulation control On / O switch.

Loss Of Charge indication (LOC)

A function is provided to indicate loss of refrigerant charge. This is only indicated by setting an alarm ag which can be accessed via modbus. No special action is performed by the controller.

External sensor values

The EIM 336 has sensor inputs for the suction pressure and evaporator temperature (S2). It is however possible to substitute these sensor inputs by sending external sensor values via modbus. These external values need to be updated frequently.

Forced opening during startup

In some applications it is necessary to open the valve quickly when the compressor turns on, to prevent too low suction pressure. This is ensured by setting a xed opening degree and a startup time for the controller. Note that this will give a xed opening degree for the duration of the start time, regardless of the superheat value.

Superheat controller, Type EIM 336

Forced opening during o

In some applications the valve must remain open when the controller is o. This can be done by setting a xed opening degree. When normal control is switched o with the main switch, the valve will keep this opening degree.

Defrost handling

The controller does not itself handle defrost of the evaporator. It is however possible to enter a special defrost sequence, which will overrule the normal control of the valve.

Standalone function

The EIM 336 is designed to operate in conjunction with a system master controller, which will control the EIM 336 via modbus. It is however possible to use it in a standalone mode with no external control, except a digital input from the Regulation control On / O switch. In this conguration some of the other functions will not be available.

Danfoss

80G39.12

AKS 11

Evaporator

EIM 336

AKS32R

ETS 6

Superheat controller, Type EIM 336

3 Applications

3.1 Regulation control

The evaporator superheat is controlled by one pressure sensor Pe (evaporator pressure) and one temperature sensor S2 (refrigerant temperature). Alternatively the pressure and temperature signals can be received as data via modbus. This can be useful if the pressure and temperature sensors are mounted on a separate controller.

Fitting the S4 (evaporator medium outlet temperature) is optional and has no eect on regulation, it is a readout value only. S4 can however be setup as a Regulation control On / O switch instead to provide an external ON/OFF function for the controller.

Figure 1: Regulation control

Danfoss

80G164.10

PWR

EEV

COM

ADR

VPT

Power Supply 24 V AC or DC

Pressure transmitter Ratiometric 0.5 – 4.5 V i.e.

AKS 32R

Temperature sensors PT 1000 i.e. AKS 11

Regulation control On/O switch (Enable

parameter HW Main Switch to 1)

Electric expansion valve ETS 6 with JST-XHP 5

connector

Features

Description

Supply voltage

24 V AC / DC (± 15%), 50 / 60 HZ, 15 VA / 8 Watt, Class II isolation

Power consumption Idle

Max. 150 mA @ 24 V DC

Operating

Max. 150 mA @ 24 V DC

Input signals For the EMC compliance, sensor cable length must be < 3m / 118 in. For longer sensor cable, a ferrite bead should be used.

AKS 32R (or similar ratiometric pressure transmitter)

PT1000 (measuring range -60 – +120°C / -76 – 248 °F)

PT1000 or digital input from external contact.

EEV driver

Max. current 150 mA RMS

EEV

Uni- or bipolar coil with JST XHP-5 connector

Data communication

RS485 – Modbus RTU (Not terminated internally)

Environment

Storage: -34 °C to 71 °C / -30 °F to 160 °F

Operating: -25 °C to 60 °C / -13 °F to 140 °F

Humidity: <95% RH, non condensing

Dimensions

25 × 50 × 80 mm / 0.98 × 1.97 × 3.15 inch

Operation

Stand alone or via Modbus data communication

Superheat controller, Type EIM 336

4 Product specication

4.1 Technical data

Table 2: Technical data

4.2 Connections

Figure 2: Stand alone conguration

Danfoss

80G15.11

PWR

POS4S2

COM

ADR

TxD+

TxD

EEV

VPM

Power Supply 24 V AC or DC

Pressure transmitter Ratiometric 0.5 – 4.5 V i.e.

AKS 32R

Modbus to master controller

Temperature sensors PT 1000 i.e. AKS 11

Regulation control On/O switch (Enable

parameter HW Main Switch to 1)

Electric expansion valve ETS 6 with JST-XHP 5

connector

MAB

Danfoss

80G166.10

PWR

COM

RS485 (-)

RS485 (+)

A B

RS485 (-)

RS485 (+)

RS485 (-)

RS485 (+)

Danfoss

80G165.10

PWR

COM

PWR

COM

Master controller

EIM slave 1

EIM slave 2

120 Ohm min. 0.25 Watt

Superheat controller, Type EIM 336

Figure 3: System conguration (default factory settings)

IMPORTANT:



• The supply voltage is not galvanically separated from the input and output signals, hence it is not recommended to use shared power supply.

• No voltage should be supplied externally, if S4 terminal is setup as a Regulation on/o switch.

• Do not reverse the polarity of the power connection cables or Modbus signal cable else it could damage the terminals.

Figure 4: Modbus one to one connection

Figure 5: Modbus in Daisy Chain



• If two EIMs are connected remember to remove the addressing jumper on one of the EIMs.

• Modbus transmission lines usually require termination resistors, especially for longer cable lengths.

4.3 Settings

NOTE:

4.3.1 Setting controller in Superheat control mode



NOTE:

Make sure that r12 = 0 (OFF) and change the settings. The setting will depends on the system requirement.

Features

Description

Enabling Regulation control ON/O switch (optional)

HwMainSwitch = 1 (default is 0, i.e S4 sensor) For standalone conguration it is recommended to enable Regulation control ON/O switch in order to control start/ stop regulation when needed, otherwise the controller will start regulating when controller is powered up.

Select Refrigerant

o30 = 1 - 42 (default value is 20 i.e R407C)

Select valve setting(optional)

n37 = 384 x 10 micro step (3840 micro steps = 480 half steps). n38 = Max. steps/sec, default value is 31 half steps For other valve type than Danfoss check the technical spec. of the valve.

Dene pressure sensor range in bar absolute (x10)

o20 = Min. Transducer pressure o21 = Max. Transducer pressure

Dene min/max superheat

n10 = min. superheat reference n09 = max. superheat reference For xed superheat dene n09 = n10

Dene MOP (optional)

n11 = maximum operating pressure (default is 12.5 bar absolute, max. 200 = MOP o)

Set force opening of the valve ( optional)

Start OD% (n17 ) StartUp time (n15)

To start the superheat control

Set r12= ON

Features

Description

Select Application mode

o18 (PNU 2075 )= 1 i.e Manual control

Select valve setting(optional)

n37 = 384 x 10 micro step (3840 micro steps = 480 half steps). n38 = Max steps/sec, default value is 31 half steps for other valve type than Danfoss check the technical spec of the valve

Select Manual opening degree

o45 Manual OD % (PNU 2064) 0 = fully closed, 100 = fully open.

Symbolic name

PNU

Description

o30 Refrigerant

2551

1 = R12 2 = R22 3 = R134a 4 = R502 5 = R717 6 = R13 7 = R13b1 8 = R23 9 = R500

10 = R503 11 = R114 12 = R142b 13 = User dened 14 = R32 15 = R227 16 = R401A 17 = R507 18 = R402A

19 = R404A 20 = R407C 21 = R407A 22 = R407B 23 = R410A 24 = R170 25 = R290 26 = R600 27 = R600a

28 = R744 29 = R1270 30 = R417A 31 = R422A 32 = R413A 33 = R422D 34 = R427A 35 = R438A 36 = Opteon XP10

37 = R407F 38 = R1234ze 39 = R1234yf 40 = R448A 41 = R449A 42 = R452A

Superheat controller, Type EIM 336

Table 3: Setting controller in Superheat control mode.

4.3.2 Setting controller in valve driver mode using Modbus signal

NOTE:



Make sure that r12 = 0 (OFF) and change the settings so they t to their application.

Table 4: Setting controller in valve driver mode using Modbus signal

By changing parameter o45 Manual OD, the valve will move accordingly regardless of r12 parameter value.

4.3.3 Selecting a refrigerant

The controller needs to know which refrigerant is used in order to accurately control the superheat. This can be selected by setting the “o30 Refrigerant” to the desired refrigerant as dened in the list below.

If no refrigerant is selected (“o30 Refrigerant” is set to 0 meaning the refrigerant is undened), the “No Rfg. Sel.” alarm is set and the controller will not start regulating.

Refrigerant setting

Before refrigeration can be started , the refrigerant has to be dened. You can select the following refrigerant.

Table 5: Related parameters



WARNING:

Wrong selection of refrigerant may cause damage to the compressor.

4.3.4 Connecting and setting up a valve

The EIM 336 controller is designed to be used with Danfoss ETS 6 valves with a maximum of 480 pulses from fully closed to fully open. This setting should not be changed.

Symbolic name

PNU

Description

n38 Max. Steps Sec.

3033

Steps per second

n39 Start BckLsh

3034

Backlash, is the additional amount of steps, in percent, to close at startup and when the valve opening degree is less than 1%.

n40 Backlash

3035

Start Backlash is the amount of steps to compensate for spindle play.

Symbolic name

PNU

Description

o20 MinTransPres

2034

Minimum transducer pressure (in bar absolute x 10). Example: 0 bar absolute is entered as 0

o21 MaxTransPres

2033

Maximum transducer pressure (in bar absolute x 10). Example: 13 bar absolute is entered as 130

Superheat controller, Type EIM 336

The speed of the valve can be changed by increasing or decreasing the number of pulses per second, “n38 Max StepsSec”. A larger value will make the valve open or close faster. Note that the torque of a stepper motor decreases as the speed increases. Too high speeds should therefore be avoided. For the ETS 6 valve, the recommended speed setting is 31 pulses per second.

When the controller is powered, the valve will rst be closed fully so that the controller starts from a known opening degree (0%). In order to make sure that it is fully closed, the valve will be closed 100% plus an additional contribution known as start backlash. The start backlash takes into account that the stepper motor may loose some steps due to too low torque or mechanical slippage in the gears etc. The start backlash is the amount of extra steps in percent to close once the valve is closed (less than 1%). If the valve is opening and reaches its destination, it will move additional steps in the opening direction, then move the same amount of steps in the closing direction. This is called backlash and is the amount of steps to add to compensate for spindle play.

Table 6: Related parameters

4.3.5 Connecting and setting up a pressure sensor

The pressure sensor input is setup by default to accept an AKS32R pressure transducer. If another sensor is to be used, it is important to note that it needs to be a 0.5 - 4.5 V d.c. ratiometric type (10% - 90% of supply voltage).

The default range for the sensor is 0 to 16 bar absolute. This can be changed by setting the minimum transducer pressure, “o20 MinTransPres” and the maximum transducer pressure, “o21 MaxTransPres” to the new values. The values must be entered in bar absolute so a sensor with a range of -1 to 12 bar gauge, needs to bedened as 0 to 13 bar absolute.

Table 7: Related parameters



NOTE:

Both Danfoss AKS 32R and Danfoss Saginomiya Pressure transmitter NSK-BExxx follows the relative (gauge) pressure, therefore same rules applies as explained above in converting and dening it in bar absolute in EIM controller.

Mounting pressure transmitter

Installation of the pressure transmitter is less critical, but mounting of pressure transmitter should be closer to the temperature sensor, right after the evaporator and with its head in upright position.

Power supply:

• Grounding of secondary (output) of transformer is not recommended.

• Do not reverse the polarity of the power connection cables and avoid ground loops (i.e. avoid connecting one eld device to several controllers as this may result in short circuits and can damage your device).

• Use individual transformers for EIM 336 controller to avoid possible interference or grounding problems in the power supply.



WARNING:

• Separate the sensor and digital input cables as much as possible (at least 3 cm) from the power cables to the loads to avoid possible electromagnetic disturbance.

• Never lay power cables and probe cables in the same conduits (including those in the electrical panels).

+ 19 hidden pages

Danfoss EIM 336 Data sheet

Specifications and Main Features

Frequently Asked Questions

User Manual