Pfannenberg FLZ 510 Enclosure Thermostat, -20 to +80 °C

Bimetal enclosure thermostats for heaters and fans

The Pfannenberg FLZ 510 family is a DIN-rail bimetal thermostat that switches the heater or the fan of a control cabinet from the temperature measured inside it. The FLZ 510 has a changeover contact, so one device can run a heater below the set point and a fan above it. The FLZ 520 has a normally closed contact for heaters and the FLZ 530 has a normally open contact for fans or filterfans. All three are set with a single dial and snap onto a 35 mm profile bar.

Paired with a heater and a filterfan it forms a simple thermal control loop with no electronics to fail.

Technical specifications

Ordering codes and temperature ranges

The article number is selected by contact type, switching range and, for the changeover version, the hysteresis. The values below are the article numbers printed on the product sheet; the dual-dial version of the 0 to +60 °C range also shows Fahrenheit on the knob.

Selecting the version and what to confirm before ordering

Use the FLZ 520 when a heater only needs to be switched off at a warm set point, for example an anti-condensation heater held between about 5 and 15 °C. Use the FLZ 530 when a filterfan should start at a higher set point such as 30 to 40 °C so that the fan stays off in cool conditions and the filter mat lasts longer. When one thermostat must drive both, choose the FLZ 510 and wire the heater to the closing side and the fan to the opening side, remembering that the two loads then share one set point; if they need different set points, use the twin thermostat version instead.

The 1 K hysteresis of the FLZ 510 gives tighter control than the 3 K version and fits sensitive electronics, while the wider hysteresis of 3 K, or below 7 K for the FLZ 520 and FLZ 530, reduces contact cycling. Use the inductive value in brackets on the datasheet for fan motors and relay coils.

Confirm the supply voltage and contact rating of the load, the required switching range, and whether a changeover, N.C. or N.O. contact is needed. The listed temperature ranges are the standard article numbers; the sheet notes that article numbers for other types are available on request. Approvals are shown on the manufacturer page for this family, including UL and a CSA certificate for the FLZ 520 and FLZ 530; check the certificate for the exact article before specifying it for a project that requires listing.

Documents and quotation

The Pfannenberg FLZ 510/520/530 product sheet is attached to this page and is the manufacturer’s own document, not a Seven Star summary. It lists all article numbers, the electrical ratings and the accessory numbers. Related thermal-management items such as filterfans and heaters are in Cooling.

Because the sheet covers three contact types and several ranges, the article number must be stated exactly on the request. Seven Star LLC, an independent supplier in Muscat, quotes the FLZ 510, FLZ 520 and FLZ 530 against your application data; send the enclosure size, ambient temperature, supply voltage and quantity so the correct variant and article number can be confirmed before an offer is issued.