Choose a Multispan water level controller by tank job: the single-tank WLC 22 automates one pump with dry-run protection, while the two-tank WLC 35 manages sump-to-overhead transfer using six conductive probes. Both are DIN-rail, 100–270 V AC.
ما هو متحكّم مستوى المياه وما وظيفته؟
A water level controller is an electronic relay that starts and stops a pump automatically based on liquid level, replacing manual switching and float switches. Multispan controllers such as the WLC 22 and WLC 35 sense level through low-voltage conductive probes (electrodes) hung at fixed heights in the tank; when water bridges a probe, the controller detects the change in resistance and switches its output relay. This automates tank filling or emptying, prevents overflow and dry running, and keeps overhead tanks topped up without an operator. In UAE buildings, villas, factories and irrigation networks, it is the small DIN-rail device inside the pump control panel that decides when the booster or transfer pump runs.
WLC 22 vs WLC 35: which Multispan model do I need?
Choose the WLC 22 for one tank and the WLC 35 when two tanks must be coordinated. The single-tank WLC 22 uses three probes (common, low, high) to control a single overhead or underground tank, filling between low and high levels with dry-run protection — ideal for a villa overhead tank or a booster set. The two-tank WLC 35 uses six probes to watch both a source tank and a destination tank at once, so the transfer pump only runs when the sump has water AND the overhead tank needs it. This is the correct model for sump-to-overhead transfer in towers across Dubai, Sharjah and Abu Dhabi, where pumping from an empty ground tank must be blocked.
كيف يعمل الاستشعار بالقطب (المجس)، ومتى ينبغي استخدام العوّامات بدلًا منه؟
Electrode sensing works by passing a tiny AC current between stainless-steel probes and reading whether water completes the circuit; it is the default for conductive water. Multispan controllers apply a safe low voltage to the probes, so there is no shock risk in the tank, and adjustable sensitivity (1–200 KΩ on the WLC 22, up to 1 MΩ on the WLC 35) tunes the trigger point to the water's conductivity. Use probes for DEWA mains water, treated water, ground/well water and most process water. Switch to float switches or capacitive/ultrasonic sensors for non-conductive or fouling liquids — deionised or RO-reject with very low TDS, oils, or foaming and sludgy media where probes can misread or scale up.
كيف أُعِدّ ملء الخزان مقابل تفريغ الخزان؟
Configure filling and emptying by probe placement and relay logic, not different hardware. For filling (the common overhead-tank case), the controller energises the pump when water falls to the low probe and stops it at the high probe, so the tank refills automatically — the WLC 22 handles this for a single tank. For emptying or de-watering a sump, the logic is inverted: the pump runs when level reaches the high probe and stops at the low probe. The common probe sets the reference. On the WLC 35, the six probes let you combine both actions — sense the source tank for dry-run and the destination tank for the fill window — which is exactly how sump-to-overhead transfer is wired in a UAE pump control panel.
كيف تمنع الحماية من التشغيل الجاف احتراق المضخة؟
Dry-run protection stops the pump whenever the supplying tank runs empty, preventing the motor and mechanical seals from overheating without water to cool them. In the WLC 22, if the source falls below the sensing probe the controller drops its relay and holds the pump off until water returns, protecting the pump from the single most common failure in the UAE's intermittent-supply buildings. In two-tank transfer, the WLC 35 blocks the transfer pump when the ground/sump tank is dry even though the overhead tank still calls for water. Because a dry pump can fail within minutes in Dubai summer heat, this level-based cut-off works alongside — not instead of — a Multispan motor-protection relay guarding against overload and single-phasing.
لماذا يهمّ تأخير الفصل لخزانات الإمارات؟
The trip delay filters out momentary false readings from wave motion, splashing and foam so the pump does not switch on and off rapidly ("hunting"). When water sloshes in a large ground tank or an inlet stream disturbs the surface, a probe can be briefly bridged or exposed; without a delay the relay would chatter, wearing contacts and stressing the pump. The WLC 22 uses a fixed delay of about 0.5 seconds, adequate for domestic tanks, while the WLC 35 offers an adjustable 0–10 second delay for large or turbulent industrial tanks. In UAE rooftop tanks exposed to vibration and in factory sumps with agitated inflow, dialling in a longer delay on the WLC 35 gives stable, contactor-friendly switching.
كيف أوصّل المُرحّل بمضخة فعلية — وهل أحتاج إلى كُنتاكتور؟
Wire the controller's relay to drive the pump directly only for small loads; use a contactor for anything larger. Both the WLC 22 and WLC 35 provide one changeover (1 C/O) relay rated 5 A at 230 V AC resistive, which comfortably switches a fractional-horsepower single-phase pump. For a typical building booster or a three-phase transfer pump — anything from roughly 1 kW upward — the controller relay should switch the coil of a Multispan or ABB/Schneider contactor, and the contactor carries the motor current. This is standard IEC control-panel practice: the level controller is the pilot device, the contactor is the power device, and a motor-protection relay sits in the motor circuit. The controllers are DIN-rail mounted (WLC 22 at 22.5 mm wide, WLC 35 at 35 mm) to sit alongside these components in the panel.
أي تطبيقات وصناعات تستخدم هذه المتحكمات في الإمارات؟
Multispan water level controllers are used anywhere a pump must follow tank level — from villas to factories to farms. In residential and commercial buildings across Dubai, Sharjah and Ajman, the WLC 22 automates overhead-tank booster pumps and underground-tank filling. In two-tank towers and district developments, the WLC 35 manages sump-to-overhead transfer and integrates into DEWA-compliant pump control panels. Industry uses them for process-water make-up, cooling-tower basins, water-treatment and RO feed tanks, and effluent/de-watering sumps. In agriculture and landscaping across Al Ain and the Northern Emirates, they control irrigation reservoir filling and drip-system supply tanks. As the authorised Multispan distributor for the UAE and GCC, Al Misbah Al Sehri supplies both models as genuine, CE-certified stock from Dubai.
