Total Dissolved Solids (TDS) Controllers - SPECTORmodul Touch | Gestra

GESTRA SPECTORmodul Touch – TDS Controllers

The LRR 1-52 / LRR 1-53 controllers, in combination with the URB 55 operator unit, are used for boiler water conductivity monitoring, continuous surface blowdown control, and MIN/MAX limit supervision. Conductivity is used as a practical indicator of TDS, as dissolved solids increase with steam generation and boiler water concentration.

Variants

• LRR 1-52: Direct input from conductivity electrodes LRG 12-2, LRG 16-4, LRG 16-9, LRG 17-1, LRG 19-1.
• LRR 1-53: 4–20 mA input from transmitters LRGT 16-1, 16-2, 16-3, 16-4, 17-3, 17-1.
• URB 55: Touchscreen display for conductivity, valve position, PI parameters, alarms, trend logging, and manual/automatic mode selection.

Control Function

The controller operates a motorized blowdown valve using 3-position stepping PI control. Intermittent blowdown can also be triggered. Alarms are generated for exceeding MAX or dropping below MIN setpoints. External standby input allows for valve closure or control deactivation.

Technical Data

• Controller supply: 24 VDC ±20%
• LRR power consumption: 5 W
• Valve outputs: 2 changeover contacts, 8 A / 250 VAC
• Analog output: 4–20 mA, actual value or manipulated variable
• LRR 1-52 range: 1–10,000 μS/cm at 25°C or 1–5,000 ppm
• URB 55: 5" display, 800 × 480 px, front protection IP66
• LRR mounting: TH 35 rail, EN 60715

Installation Notes

LRR is panel-mounted; URB is door-mounted. Electrode cables must be shielded and routed separately from power cables. Max cable length to electrode: 30 m (or 10 m for 1–10 μS/cm). Not suitable for hazardous areas.

FAQ

When to select LRR 1-52?
For direct measurement from LRG electrodes.

When to select LRR 1-53?
When a LRGT transmitter with 4–20 mA output is used.

Does it provide automatic MAX lockout?
No. If lockout is required, implement in downstream safety circuit per EN 50156.