Bieler+Lang GMC 8034 — 4-channel gas controller

A controller for four 4–20 mA sensors. Three alarm levels on every channel, ten freely configurable relays and a display whose backlight changes colour with the status — you can see what is going on from across the room.

Four channels, three levels

The GMC 8034 handles up to four detectors and distinguishes three alarm levels plus a sensor fault on each of them. That lets the response be staged: alarm 1 starts the ventilation, alarm 2 switches on the visual and audible signalling, alarm 3 cuts the gas supply and shuts equipment down.

Ten floating contacts can be assigned freely — there is no fixed "this relay is the horn". When an installation is being designed, that is the difference between fitting the controller to the building and fitting the building to the controller.

The colour-changing display

The four-line LCD shows the concentration and the programming data, and the backlight changes colour with the status: one colour for an alarm, another for a fault, another for a special state. Operation comes down to a single rotary encoder — turn and press, with no button layout to learn.

24 V supply — what that changes

The controller runs on 24 VDC from a SELV or PELV supply. It therefore plugs into the existing safety circuit in the automation cabinet, and backup power is an ordinary 24 V battery — no 230 V UPS needed.

8034 or 8022

For two measuring points and simple "alarm — shut off" logic the GMC 8022 is enough. The GMC 8034 is the choice when there are three or four points, when a third level is needed, or when more than four separate reactions have to be wired.

Technical data

Parameter	Value
Type	gas controller for top-hat rail mounting
Channels	4
Measuring inputs	4 × 4–20 mA signal
Alarm levels	3 per channel — alarm 1, 2 and 3 plus sensor fault
Relay outputs	10 floating contacts, freely configurable
Contact rating	max. 230 VAC / 3 A (cosφ 0.7) · 30 VDC / 3 A; min. 5 VDC / 10 mA
Relay overvoltage category	III
Supply voltage	24 VDC (21.5–28.8 VDC), SELV or PELV power supply, overvoltage category II
Display	4-line LCD, 4-colour backlight — alarm, fault, special status
Indication	LEDs per channel (alarm 1–3, fault, displayed sensor), ready, device or sensor fault, service message, relay status
Controls	rotary pressure encoder
Manufactured in	Germany

Service with us

We are an authorised Bieler+Lang trade and service partner — we hold the manufacturer's written authorisation covering commissioning, maintenance and other service work, valid until 31 December 2028. Our technicians were trained in Achern and work with original parts and factory procedures.

In practice that means we commission, calibrate and service what we sell — nothing has to be shipped back to Germany. See our service scope or send equipment in.