H2scan HY-ALERTA 2620 Explosion Proof Hydrogen Monitor

An AC-powered explosion proof hydrogen monitor with relay-level outputs

HY-ALERTA 2620 is the explosion proof fixed area hydrogen monitor in the H2scan HY-ALERTA range. It measures 0.4% to 5% hydrogen (10% to 125% of the lower explosive limit) with a solid-state hydrogen-specific sensor, so that hydrogen can be monitored in areas where other combustibles are present without cross-sensitive nuisance alarms, according to the datasheet.

Unlike the 600B it runs directly from 90 to 240 VAC at 15 W, offers three programmable relays rated 5 A at 240 VDC with both NO and NC contacts, and has a 4-20 mA analog output with RS232 or RS422 serial. The datasheet lists indoor or outdoor use and states the enclosure is IP67 rated.

Technical specifications

The accuracy formula means the permitted error grows with the reading: at 1% H2 it is 0.23% and at 5% H2 it is 0.35% (derived from the printed formula).

When to pick the 2620 instead of the 600B

• Choose the 2620 where the monitor itself must be installed in a classified location; the 600B datasheet shows no hazardous-area rating.
• Choose it where 90 to 240 VAC mains is available and a 24 V supply would otherwise need a separate power unit.
• Choose it for heavier switching: its 5 A / 240 VDC relays can drive contactors or beacons directly, whereas the 600B relays are rated 1 A / 30 VDC.
• Choose the 600B instead where a small DC-powered unit in a non-classified room is enough.

Applications in power, gas and battery installations

The manufacturer lists hydrogen-cooled generators and turbines, battery rooms during lead acid charging, analyzer buildings and control rooms, laboratories, refueling stations, electrolyzers and fuel cells, hydrogen storage and piping, and furnaces. Hydrogen-cooled generators in Gulf power stations and electrolyzer pilot sites are natural fits for an AC-powered, explosion proof unit.

Install at the height and location specified by your hazardous-area drawings, calibrate every 90 days with air background gas, and record the 4-20 mA scaling (0 to 5% H2) in the control system. Compare other detectors in the fire and gas detectors category.

Specification reading guide and commissioning notes

The 2620 shares its measurement core with the 600B, so range, T90 and accuracy are identical, while the housing, supply and relays differ. Its enclosure is 190.5 x 137.16 x 144.78 mm, the same outline the datasheet gives for the HY-OPTIMA 2700 analyzer housing, which helps when planning panel and bracket space for both devices.

During commissioning, set alarm levels on the three relays, verify the NO and NC contact wiring against the control logic, and configure the 4-20 mA output span. A hydrogen leak scenario in a turbine hall may need a first alarm for operator attention and a second for ventilation; the datasheet gives the hardware, but the thresholds must come from your hazard study.

Certificates are quoted on the datasheet only as listed above; request the full certificate set and conditions of use from the manufacturer before installation in a Zone 1 or Division 1 location.

Spare parts such as relay logic, power supply and sensor assemblies are not listed in the datasheet, so ask for the manual and recommended spares list when quoting.

Document control: the datasheet used here is H2scan document 90000239, dated 09.25, and it covers three area monitors in one selection table. Quote the certification entries from the 2620 column only, and ask the manufacturer for the 2620 manual and full certificates before you design wiring, glands and alarm settings.

Installation in hazardous areas

The 2620 carries Ex db flameproof protection, so field wiring enters through certified cable glands or conduit seals that match the enclosure threads and the area classification. General engineering note (not from the datasheet): keep the flameproof joints clean and undamaged, do not open the enclosure while energised in a hazardous area, and include the unit in the site inspection programme for Ex equipment.

Hydrogen is far lighter than air and has a lower explosive limit of about 4% by volume, so area monitors are normally mounted high, above the likely leak source. The three 5 A relays allow the monitor to start exhaust fans, close a supply valve and send a common alarm directly, without waiting for the control system. The operating range is -20 to 55°C; in exposed outdoor locations in Oman and the GCC, a sun shade helps keep the enclosure within this limit during summer. Test relay actions at every 90-day calibration.

Frequently asked questions

Is the HY-ALERTA 2620 explosion proof? Yes. The datasheet lists C/UL Class I Div 1 Groups B, C, D, ATEX II 2 G Ex db IIB + H2 T4 Gb and IECEx Ex db IIB + H2 T4 Gb.

What supply voltage is used? 90 to 240 VAC at 15 W input power.

What detection range applies? 0.4 to 5% hydrogen, which is 10 to 125% of the lower explosive limit.

What relay rating is available? Three programmable relays rated 5 A at 240 VDC with NO and NC contacts.

What is the response time? T90 below 60 seconds.

Documents and quotation

The H2scan HY-ALERTA datasheet is attached. Seven Star LLC is an independent supplier in Muscat. Send the area classification, supply voltage and output requirements to request a quotation for the HY-ALERTA 2620.