Danfoss Liquid Level Alarms, Safety Switches, Liquid Level Regulators

RT 280A and 281A are primarily used as liquid level alarms and safety switches to prevent too high a liquid level in liquid separators. Secondarily, RT 280A and 281A can be used as liquid level regulators where a liquid level differential of up to 40 mm can be permitted
RT 280A and 281A used as safety switches ensure that the max. Permissible refrigerant le- vel in flooded evaporators, pump tanks or liquid separators is not exceeded.
As liquid level regulators, RT 280A and 281A maintain a constant average refrigerant level in flooded evaporators, pump tanks or liquid separators.

Materials Gaskets are non-asbestos.

Technical data
1. General
Refrigerants
R 717 (NH3), R 22 and R 502
Other refrigerants
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Operating ranges for RT 280A
R 12: 50 +10 C
R 22 og R 717 (NH3): 50 0 C R 502: 65 5 C
Operating ranges for RT 281A
R 22 and R 717 (NH3): 30 +20 C
Liquid level differential
With a steady liquid level and a liquid level variation rate of max. 15 mm / min, the
Differential will be approx. 10 mm on a rise in level and approx. 20 mm on a fall in level.
In unfavourable operating conditions, differentials of approx. 20 mm on a rise in
Level and approx. 60 mm on a fall in level must be expected.
Ambient temperature
50 +70 C
Switch
Single pole changeover switch (SPDT),
Code no. 017-4030
Approvals
CE-approved according to EN 60947-4, -1
EN 60947-5, -1
Meet the requirements of VDE 0660
(VDE: Verband Deutscher Elektrotechniker)
Contact load Alternating current AC1: 10 A, 400 V AC3: 4 A, 400 V AC15: 3 A, 400 V
Max. Direct current
DC13: 12 W, 220 V

Short-time AC 3 current: 28 A
Weight
2.0 kg
Enclosure
IP 66 to IEC 529.

2. Pressure element
Pressure connection
G 3/8 A with 6.5 / 10 mm weld nipple

Max. Working pressure
PB = 22 bar

Max. Test pressure
P' = 25 bar

3. Thermostatic element
Adsorption charge
3 m capillary tube
Max. Permissible bulb temperature: +80 C

4. Bulb with electric heater
10 W heater for 24 V d. C. Or a. C. The heater
Must be constantly energized whilst the system is in operation. 1.5 m connection cable.