Type Y1A8G & Y1B8G: “Pigtail” bulb room thermostats


Wall mounting for indoor or outdoor temperature control of cold rooms.

– Temperature control of industrial or commercial premises.

– Outdoor temperature control of antifreeze heaters.

– Green houses and livestock stables temperature control.


Housing: Aluminum, IP65, IK10. Mounted on a SUS304 stainless steel wall mounting plate which keeps the temperature sensing element away from the wall. Grey RAL7032 epoxy painting. Stainless steel captive cover screws. Captive aluminum lid.

Set point adjustment ranges: 4-40°C (40-105°F)

Set point adjustment:  By °C printed knob. All types have an adjustable rotation limit system located inside the knob that allows reducing the set point adjustment span. Types with external adjustment have a transparent window. This device allows seeing the pilot light and the knob position.  °F values are available as an option.

Action: Temperature control.

Sensing element: Liquid filled “pigtail” bulb, mounted on the side of plastic housing.

Electrical connections:  Inside, on screw terminal connection block.

Earthing:  Internal and external screw terminal.

Pilot light: Allow to visualize thermostat contact output position. Standard for all models with transparent window. Non Standard and on special request only for models with plain aluminum cover. 

Cable input and output: Two M20 cable glands, Black PA66.

Mounting: Wall mounting, by 4 holes for screws, Black PA66.

Mounting: Wall mounting, by 4 holes for screws dia. 4 to 5 mm, 94 x 92 mm distance.

Identification: Metallic identification label, riveted.

Contact: SPDT

Electrical rating, resistive loads:

 –Open on temperature rise contact (C-1)

16A 250V, 50 ~60Hz: >100000 cycles,

20A 250V, 50 ~60Hz: ≥ 50000 cycles,

10A 400V, 50 ~60Hz: ≥ 50000 cycles.

-Close on temperature rise contact (C-2): 6A 250V 50 ~60Hz: >100000 cycles

Electrical rating, inductive loads:

 –Open on temperature rise contact (C-1): 6A 250V, 50 ~60Hz: >100000 cycles

-Close on temperature rise contact (C-2):0.6A 250V 50 ~60Hz: >100000 cycles. 

Minimum storage temperature: -35°C (-30°F)

Maximum ambient temperature: 60°C (140°F)

For more technical information see 8G thermostat technical data sheet (catalog 1).


Main references

Temperature adjustment ranges

°C (°F)

References with external adjustment References with internal adjustment

Differential °C (°F)

4-40°C (40-105°F)

Y1B8G4040AQ30001J Y1A8G4040AQ30001J

1,6±1°C (2,9±2°F)

°F printing: replace last character (J) by K



2D&3D Drawing