Danfoss AKS 4100U Data sheet

Data sheet

Liquid Level Sensor

Type AKS 4100U

AKS 4100U - Coaxial VersionAKS 4100U - Cable Version

The AKS 4100U liquid level sensor is designed specically to measure liquid levels in awide range of refrigeration applications.

The AKS 4100U liquid level sensor is based on a proven techhology called Time Domain Reectometry (TDR) or Guided Micro Wave.

AKS 4100U liquid level sensor can be used to measure the liquid level of many dierent refrigerants in vessels, accumulators, receivers, standpipes, etc.

The electrical output is a 2-wired, loop powered 4 – 20 mA output signal, which is proportional to the refrigerant liquid level.

AKS 4100U in a cable version is suitable for HCFC, Non ammable HFC and R717 (Ammonia), and diering lengths from 800 mm / 31.5 in. and up to 5000 mm / 197 in..

The coaxial version of AKS 4100/4100U is designed for use with R744 (CO2), HCFC, Non ammable HFC and R717 (Ammonia).

The AKS 4100U coaxial version should always be used for marine applications for all refrigerant types.

The AKS 4100U cable version should NOT be used for CO2 or marine applications.

Dust, foam, vapour, agitated surfaces, boiling surfaces, changes in density or in the dielectric constant , εr, for the liquid have no inuence on the AKS 4100U performance.

Oil accumulated in the bottom of a standpipe will not disturb the liquid level signal and it is not necessary to remove AKS 4100U for cleaning after oil has been drained out of the standpipe.

Features

y One product covering several probe lengths (cable

version)

y A single product for all commonly used refrigerants

(cable version)

y Cable version requires less top-end clearance for

installation and service

y Proven operation with all refrigerants in combina-

tion with oil.

y No need to clean cable version when fully covered

by oil.

y The cable version is very compact and easy to

handle, ship, install and use with dierent lengths and refrigerants

y Changes of the liquid dielectric constant (εr) do not

aect operation.

y 5000 mm / 197 in. probe length with cable version

y 2-wire loop powered; no separate transformer

needed. Please Note:

AKS 4100U can be connected directly to Danfoss EKE 347 liquid level controller and thus be powered from EKE 347.

If used together with Danfoss EKC 347 liquid level controller, a 14 – 30 V DC supply is required.

y Multi language HMI. Level and setting readout in

mm,cm,m (ft, in.) Language HMI versions:

- English (default), German, French, Spanish

- English (default), Japanese, Chinese Russian

For further details regarding mechanical and electrical installation please refer to the product installation guides DKRCI.PI.SC0.D (CABLE version), DKRCI.PI.SC0.E (COAXIAL D14 version) and DKRCI.PI.SC0.H1/DKRCI.PI.SC0.J1 (COAXIAL D22 version).

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Data sheet | Liquid Level Sensor, type AKS 4100U

Contents Page

Features ................................................................................................................................................................................................. 1

Product concept

CABLE version .............................................................................................................................................................................. 3

Cable version ................................................................................................................................................................................ 3

Optional HMI ....................................................................................................................................................................................... 5

Measuring principle ......................................................................................................................................................................... 6

Main technical data ........................................................................................................................................................................... 6

Measuring range:

CABLE version .............................................................................................................................................................................. 7

COAXIAL D14 version ................................................................................................................................................................ 8

COAXIAL D22 version ................................................................................................................................................................ 8

Ordering AKS 4100U ......................................................................................................................................................................... 9

Dimensions and weights ...............................................................................................................................................................10

Technical data ................................................................................................................................................................................... 11

Quick setup:

CABLE version ............................................................................................................................................................................ 13

COAXIAL version .......................................................................................................................................................................14

Forcing mA output ..........................................................................................................................................................................16

Entering refrigerant dielectric gas constant ..........................................................................................................................17

Saturated vapour dielectric constant .......................................................................................................................................18

How to change the language setting (Default: English)....................................................................................................19

Reset to factory setting ..................................................................................................................................................................19

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Data sheet | Liquid Level Sensor, type AKS 4100U

Product concept

AKS 4100U is available in two dierent versions:

y Cable version y Coaxial version

CABLE version: COAXIAL D14 version

(14 mm / 0.55 in. tube diameter):

Both Cable and Coaxial versions are available with mechanical process connection:

y AKS 4100U: ¾ in. NPT

COAXIAL D22 version (22 mm / 0.87 in. tube diameter):

D22 marking

Cable version

The cable version consists of:  Signal converter, which can be supplied with or without HMI  Mechanical process connection with 5 m / 197 in. ø2 mm / 0.08 stainless cable

 Counterweight  Accessory bag comprising:

3 mm set screws Red cover to protect mechanical process connection  prior to mounting signal converter. Setting label.

With the cable version it is possible to adapt the AKS 4100U to any possible length in the range of 800 mm / 31.5 in. to 5000 mm / 196.9 in.

Cable version can be used in R717 / NH3, HCFC and HFC (εr, liquid > 5.6).

AKS 4100U cable version must ALWAYS be installed in a level column 2 in. to 4 in. in size.

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Data sheet | Liquid Level Sensor, type AKS 4100U

Coaxial version

Coaxial D14 version (see page 3)

The Coaxial version consists of:

 Signal Converter (with or without HMI)  Mechanical process connection with

5 m / 197 in., Ø2 mm / 0.08 stainless wire

AKS 4100U, Coaxial can be installed in a level column (a) or directly in a vessel (b).

 Tube(s) depending on required length  Accessory bag comprising:

End Connector (incl. 3 mm / 0.12 in. set screws.) 3 mm / 0.12 in. set crews (1 set screw pr. tube) Red cover to protect mechanical process connection , before Signal Converter

is mounted. Setting label.

Coaxial D22 version (see page 3)

The Coaxial D22 version consists of:

 Signal Converter (with or without HMI)  Mechanical process connection 280 mm /

11 in.. 8 mm / 0.3 in. inner rod.

The coaxial version is mandatory for use in:

- R744 / CO2 (εr, liquid > 1.3).

- Marine applications

The coaxial version can also be used in the refrigerants: R717 / NH3, HCFC and HFC.

The coaxial version is available in the following probe lengths:

Danfoss type Tube diameter Type selection in HMI Thread

AKS 4100U, 11.0 in. 22 mm 0.87 in. D22 ¾ in. NPT AKS 4100U, 19.2 in. 14 mm 0.55 in. D14 ¾ in. NPT AKS 4100U, 30 in. 14 mm 0.55 in. D14 ¾ in. NPT AKS 4100U, 45 in. 14 mm 0.55 in. D14 ¾ in. NPT AKS 4100U, 55 in. 14 mm 0.55 in. D14 ¾ in. NPT AKS 4100U, 65 in. 14 mm 0.55 in. D14 ¾ in. NPT AKS 4100U, 85 in. 14 mm 0.55 in. D14 ¾ in. NPT

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Data sheet | Liquid Level Sensor, type AKS 4100U

Optional HMI

The optional HMI Service/Display unit is used for commissioning and quick on-site setup and is easily mounted on the AKS 4100U.

Enter menu system Enter QUICK SETUP

AKS 4100

Unit change at distance/level readout:

m, cm, mm, in, ft

Change between:

Distance* Level** Output (%)*** Output (mA)****

* DISTANCE is a display option. If the display is set to “DISTANCE” the displayed value will be the distance from the Reference point to the top surface of the liquid refrigerant (see pages 7 and 8).

** LEVEL is display option. If the display is set to “LEVEL” then the value displayed will be: PROBE LENGTH (entered in QUICK SETUP) – DISTANCE (see pages 7 and 8)

The service unit supports mulitple languages in both SI and US units.

 4 – 20 mA output displayed as bar graph



and in percentage [%]

 Measurement name (in this example,



DISTANCE)

 Device tag name



Measurement reading and unit



Device status (markers)



Marker 1, 2 and 3 (Error)

Hardware problem; the Signal Converter hardware is defective. Contact Danfoss.

Marker 4 and 5 (Notication)

Depending on the level, the marker is ON or OFF. Used for Danfoss service information only.

Keypad buttons



Flashing star indicating unit in operation.



*** OUTPUT (%) is display option. Will represent the level of refrigerant,in percent, scaled (entered in QUICK SETUP) according to: SCALE 4 mA (0%), SCALE 20 mA (100%) (see pages 7 and 8).

**** OUTPUT I (mA) is display option. Will represent the level of refrigerant,

in 4 – 20 milliampere, scaled (entered in QUICK SETUP) according to: SCALE 4 mA (4 mA), SCALE 20 mA (20 mA) (see pages 7 and 8).

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Data sheet | Liquid Level Sensor, type AKS 4100U

Measuring principle (Cable and Coaxial)

1. The electromagnetic (EM) pulse is

transmitted by the signal converter

2. The pulse goes down the probe at the speed of light in air, V1

3. The pulse is reected

4. The pulse goes up the probe at

speed, V1

5. The converter receives the pulse and records the signal

6. The EM pulse moves at speed, V1

7. Transmitted EM pulse

8. Half of this time is equivalent

to the distance from the reference point of the device (the ange facing) to the surface of the product

9. Received EM pulse

The AKS 4100U electronic converter emits lowintensity, high frequency electromagnetic pulses with a width of approximately 1 nanosecond, which travel at the speed of light along the probe (wire or coaxial cable) down to the liquid surface.

The pulses are reected by the liquid surface, guided back along the probe, and received and analysed by the AKS 4100U electronic converter and then converted into a liquid level reading. This method is called time domain reectometry (TDR) or guided microwave.

The dielectric constant, εr, of the liquid is a key parameter and has a direct impact on the degree of reection of the high frequency electromagnetic pulses. Liquids with high εr values, such as ammonia, produce strong reections, while liquids with low εr values, such as CO2, produce weak reections.

As long as the εr value of the liquid refrigerant is higher than 1.2, AKS 4100U can detect the liquid level and level measurement accuracy is not aected.

If the temperature condition in the standpipe/vessel is known, a constant (dielectric constant of the refrigerant gas) can be entered (parameter 2.5.3 GAS EPS.R), in order to obtain improved Top and Bottom Dead Zone values.

Refer to pages 7 to 8 for Measuring range of AKS 4100U - CABLE version and COAXIAL version.

For details of gas constant values for dierent temperatures and refrigerants plus the procedure

for

entering these via the HMI, refer to pages 17 to 18.

Main technical data

(see a complete list of all technical data on page 11)

) AKS 4100U Coaxial 11 in are only

released for R717/NH

Supply Voltage

14 – 30 V DC. Min / Max. Value for an output of 22 mA at the terminal.

Ambient temperature supply voltage limitations:

-40 – 80 °C / -40 – 176 °F : 16 – 30 V DC

-20 – 80 °C /-4 – 176 °F : 14 – 30 V DC

Load

RL [Ω] ≤ ((Uext -14 V) / 20 mA). – Default (Error output set to 3.6 mA) RL [Ω] ≤ ((Uext -14 V) / 22 mA). – (Error output set to 22 mA)

Cable gland

AKS 4100 PG 13, M20×1.5 ; (cable diameter: 6 – 8 mm / 0.24 – 0.31in. AKS 4100U ½ in. NPT

Refrigerant temperature

-60 – 100 °C / -76 – 212 °F Ambient temperature

-40 – 80 °C / -40 – 176 °F For HMI : -20 – 60 °C / -4 – 140 °F

Process pressure

-1 – 100 barg / -14.5 – 1450 psig

Terminals (spring loaded)

0.5 – 1.5 mm² (~20-15 AWG)

Enclosure:

IP 66/67 (~NEMA type 4X)

Mechanical connection Cable version / Coaxial version:

AKS 4100U: ¾ in. NPT

Refrigerants 1)

The listed refrigerants are qualied and approved by Danfoss R717 / NH3 -40 – 50 °C / -40 – 122 °F R744 / CO2 -50 – 15 °C / -58 – 59 °F

HCFC: R22 -50 – 48 °C / -58 – 118 °F HFC: R404A -50 – 15 °C / -58 – 59 °F R410A -50 – 15 °C / -58 – 59 °F R134A -40 – 50 °C / -40 – 122 °F

The listed refrigerants may be used in the complete temperature range of AKS 4100U, however, the accuracy may be aected if the above listed temperature range is exceeded.

Other refrigerants within the groups of HCFC and HFC can be detected and measured if the following conditions are fullled:

Reference conditions

Dielectric constant Cable version can be used in R717 / NH3, HCFC and HFC (εr, liquid > 5.6 ).

The coaxial version is mandatory for use in:

- R744 / CO2 (εr, liquid > 1.3).

- Marine applications. The coaxial version can also be used in the refrigerants:

R717 / NH3, HCFC and HFC.

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