Custom PCB Design for Water Utilities
Water-utility electronics fail in ways bench prototypes never show: condensation under conformal coat, ingress past a connector gland, or a galvanic ground loop between a buried sensor and a powered metering board. We design submersible and wet-service PCBs from the potting and sealing strategy inward, so the board is built for the vault, well, or sump it will actually live in.
Challenges specific to Water Utilities
Condensation kills sealed boards
A nominally watertight enclosure breathes with day/night temperature swings, pulls in humid air, and condenses water directly on the PCB even though nothing leaked.
Connector glands are the real leak path
Boards survive but cable entries do not: water wicks along stranded conductor cores past the gland and tracks into the enclosure along the wire itself.
Ground loops corrode buried sensors
A few millivolts of potential between a metering board ground and a submerged probe drives galvanic current that eats the sensor electrode and skews readings over months.
Pressure crushes potted modules
Deep-well and reservoir deployments see static head pressure that deforms voids in cheap potting, fractures solder joints, and delaminates conformal coatings under cyclic load.
4-20mA loops pick up pump noise
Long sensor runs near VFD-driven pumps inject common-mode noise that corrupts level and flow readings unless the analog front-end is galvanically isolated.
Chlorine and biofilm attack copper
Residual chlorine, H2S off-gassing in sumps, and biofilm create a corrosive micro-environment that lifts pads and grows dendrites across exposed copper within a season.
How GizanTech solves them
- Two-part epoxy potting with void control. We spec vacuum-degassed two-part epoxy or polyurethane potting matched to the board's thermal load, eliminating voids so condensation has no surface to form on and joints carry no head pressure.
- IP68 sealing and gland-side dam. We design to IP68 with cable-entry potting dams and individually sealed conductors, so even if water wicks down a cable core it stops at an epoxy barrier before reaching live copper.
- Galvanic isolation of sensor front-ends. Submerged probes get isolated ADC front-ends with isolated DC-DC and digital isolators, breaking the DC path that drives electrode corrosion and rejecting pump-side common-mode noise.
- Pressure-tolerant stackup and joint design. We use thicker copper, teardrop pads, and compliant component placement so potted assemblies tolerate cyclic head pressure to rated depth without solder-joint fracture or coating delamination.
- Isolated 4-20mA / RS-485 loop interfaces. Industrial loop and bus interfaces are isolated and surge-protected per IEC 61000-4-5, so VFD noise and long buried runs do not corrupt level, flow, or pressure telemetry.
- Corrosion-hardened finishes and coatings. We specify ENIG finish, no-clean assembly, and Parylene or acrylic conformal coat under potting to resist chlorine, H2S, and biofilm-driven dendrite growth in wet vaults.
| Design rule | Target | Failure mode in water service | Design action |
|---|---|---|---|
| Potting / encapsulation | Voidless two-part epoxy, full board fill | Voids trap air, condense water, then crack joints under thermal cycling | Vacuum-degas potting; match CTE to board; design for full encapsulation |
| IP68 sealing | IP68, >=1m / 24h immersion | Connector glands and seams admit water that breathing pressure draws in | Potted cable-entry dam, gasketed seams, individually sealed conductors |
| Pressure tolerance | Rated to deployment head (e.g. 3 bar / 30m well) | Static head deforms potting voids, fractures solder, delaminates coating | Thicker copper, teardrop pads, compliant placement, voidless fill |
| Sensor front-end isolation | Galvanic isolation >=1.5kV, isolated DC-DC | Common-mode pump/VFD noise and DC offset corrupt analog readings | Isolated ADC + digital isolators + isolated supply on the probe rail |
| Ground-loop control | Single-point ground, <5mV probe-to-board offset | Galvanic current corrodes buried electrodes and skews telemetry | Break DC path with isolation; single-point earth; no shared analog return |
| Surge / EMC | IEC 61000-4-5 surge, IEC 61000-4-2 ESD | Pump switching surges and lightning on long buried runs blow inputs | TVS + gas-discharge on loop/bus inputs; isolated, fused interfaces |
Custom PCB Design for other industries
Frequently asked questions
Can you design a board that survives full submersion in a well?
Yes. We design potted, IP68-rated assemblies validated to the static head pressure of your deployment depth, with cable-entry dams so water cannot wick in along conductor cores.
How do you stop condensation inside a sealed water-meter enclosure?
We eliminate the air gap with voidless potting so there is no internal surface for water to condense on, and where venting is required we spec hydrophobic breathable membranes.
Why are my buried level sensors corroding and drifting?
Almost always a ground loop. We isolate the sensor front-end so no galvanic DC flows between probe and board, which stops electrode corrosion and the slow reading drift it causes.
Do you handle 4-20mA and RS-485 interfaces for SCADA integration?
Yes. We design isolated, surge-protected 4-20mA, RS-485, and Modbus interfaces per IEC 61000-4-5 so pump-VFD noise and long runs do not corrupt telemetry to your SCADA.
What conformal coating do you use for chlorinated and H2S environments?
We typically specify Parylene or acrylic conformal coat under full potting, with ENIG finishes and no-clean assembly, to resist chlorine, H2S, and biofilm-driven dendrite growth.