The L Series, L7, LM7 and LM8, is a family of fixed setting temperature limit controls whose design is failsafe. The L7 is auto reset, whilst LM7 and LM8 are manual reset. The operating temperatures are factory set and non-adjustable by the customer. Settings are available between 50 and 160ûC with capillary lengths from 450 - 2000mm (1000 mm standard). The L7/LM7 are SPST (single pole singlethrow) and LM8 is DPST (doublepole single throw).

DESIGN FEATURES

• Element
• Auto or manual reset
• Fail-safe (cut-out to safety)
• 16(3)A 400V ~.  For LM8 ratings apply to each pole
• Variety of settings and capillary options
• Narrow profile to fit applications where space is limited
• Versions available for Class I and Class II appliances
• Versions for millivolt circuits(L7/LM7 only) available
• Simple mounting

APPLICATIONS

These controls are used on any application where protection against overheat is required. Typical applications are:

• 'Boil dry' protection for waterheaters, washing machines,dishwashers, vending machines (protection of heating elements)
• high temperature cut-out oncentral heating boilers
• blocked flue sensor on boilers with natural draft (on operation the gas supply to the burner is switched off)
• protection against overheating in panel/convector heaters
• overheat safety for AC cassette units equipped with an electric boost heater
• overheat safety on compressor discharge pipes

TECHNICAL SPECIFICATIONS (see dimensions also)

Electrical Rating

L7/LM7: 16A 400V~ resistive

3A 400V~ inductive

LM8: ratings apply to each pole

Switch

SPST break on rise of temperature

DPST (LM8) break on rise of temperature (note: for millivolt applications L7/LM7 can be supplied with goldplated contacts)

Terminals

Tab 6,3 mm

Terminal Configuration

As shown, earth terminals available if required

Approvals

Approved throughout Europe

Special versions approved for North America (see chart)

Maximum Head Temperature

At least 15°C below sensed temperature, max. 90ºC

TECHNICAL SPECIFICATIONS

Temperature Range

Fixed settings between 50ºC and 160ºC to order (factory set)

Tolerances

Standard ±8ºK On models with cut-out temperatures, 50 - 115ºC ±­3ºK is available

Capillary Length

450 and 2000 mm (in accordance to customer specification)

Capillary Insulation

Available on request

TECHNICAL SPECIFICATIONS

Capillary Form

Straight or coiled (minimum diameter 6 mm) Approximately 400 mm of capillary or the complete sensing element is required for optimum sensing

Cross Ambient

Cross ambient versions with solid bulbs are available (LM7 and LM8 only). Temperature range 50 - 130ºC. The following information should be supplied with every enquiry:

• Application
• Model L7, LM7 or LM8
• Setting required
• Capillary length and sensing element (for options see Fig.3)
• Control switch temperature
• Mounting requirement (for options see Fig.2)
• Capillary insulation

Barometric Effect

The control is calibrated to cut-out within the specified tolerance at a barometric pressure of 760 mm Hg. For pressure higher (or lower) than this add (or subtract) 1ºC for every 25 mm Hg change.

This control must be applied and installed in line with local approvals and practices. Suitable earthing must be made by appliance manufacturer and installer.