Description
Product Overview
The GESTRA NRS 1-50 Level Switch is a safety-related water level monitoring device designed for steam boilers and pressurized hot-water installations. Used with compatible GESTRA NRG level electrodes, it detects when the water level falls below a defined minimum and initiates a low-water alarm and heating shutdown through the connected safety circuit.
The NRS 1-50 includes automatic self-monitoring functions to detect certain faults in the level switch, electrode, or electrical connections. It also provides status indicators and test functions to support commissioning and maintenance.
The model is available in configurations for one or two electrodes. Confirm the exact version, supply voltage, electrode arrangement, and approval requirements before ordering or replacing an existing unit.
Gestra NRS 1-50
Key Features
- Low-Water Level Protection: Detects when the water level falls below the configured minimum.
- Boiler Safety Application: Designed for compatible steam boilers and pressurized hot-water systems.
- Electrode-Based Detection: Works with compatible GESTRA NRG level electrodes.
- Automatic Self-Monitoring: Monitors relevant safety functions and can trigger a shutdown in response to detected faults.
- Safety Circuit Outputs: Provides switching contacts for integration into an external safety circuit.
- Diagnostic Functions: Includes test controls and visual status indicators.
- Flexible Supply Options: Available with 24 V DC supply, with an optional 100–240 V AC version depending on configuration.
- DIN Rail Mounting: Designed for installation in a control cabinet on a TH 35 support rail.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | GESTRA |
| Model | NRS 1-50 |
| Series | Water Level Limiter |
| Product Name | Level Switch / Low-Water Level Limiter |
| Product Type | Safety-related boiler level monitoring switch |
| Electrode Configuration | One- or two-electrode version, depending on model |
| Compatible Electrode Family | GESTRA NRG 1…-50; compatibility depends on configuration |
| Supply Voltage | 24 V DC ±20%; optional 100–240 V AC, 47–63 Hz |
| Current Consumption | 0.3 A at 24 V DC; 0.2 A for the optional AC version |
| Power Consumption | Approximately 7 W/VA, depending on version |
| Safety Circuit | Two potential-free normally open contacts |
| Contact Rating | Up to 6 A at 250 V AC or 30 V DC, subject to specified load conditions |
| Response Delay | 3 seconds in the documented standard configuration; marine applications may use a different setting |
| Signal Outputs | Two outputs for external signaling; electrical details depend on version |
| Mounting | TH 35 DIN rail |
| Dimensions | Approximately 100 × 74 mm front dimensions; confirm full installation dimensions |
| Place of Manufacture / Origin | Germany is associated with GESTRA; unit-specific origin not verified |
| Product Status | Confirm actual item condition with seller |
| Weight | Not verified |
| Country of Origin | Confirm from the product label |
| Discontinued | Current lifecycle status not verified |
Specifications may vary by product generation, electrode configuration, and supply option. The exact unit’s nameplate and applicable installation manual take precedence.
Typical Applications
- Steam boiler low-water protection
- Pressurized hot-water installations
- Boiler heating shutdown circuits
- Industrial steam generation systems
- Marine and industrial boiler control systems
- Maintenance and replacement of compatible GESTRA level monitoring equipment
Frequently Asked Questions
Q1: What is the GESTRA NRS 1-50 used for?
It monitors water level through compatible level electrodes and helps protect boilers by initiating an alarm and heating shutdown when the water level falls below the required minimum.
Q2: Does the NRS 1-50 require a separate level electrode?
Yes. It operates with compatible GESTRA NRG level electrodes. The number and type of electrodes depend on the specific NRS 1-50 version and application.
Q3: What power supply does it require?
The documented DC version uses 24 V DC ±20%. An optional 100–240 V AC version is also documented. Confirm the supply specification on the actual unit before wiring.
Q4: Can it be used as a direct replacement for another NRS 1-50?
Potentially, but the electrode configuration, supply voltage, response settings, approvals, and wiring must match the installation requirements.
Q5: Does it automatically reset after a low-water alarm?
Reset behavior depends on the complete safety circuit and installation design. The required external interlock and reset arrangements must follow the applicable standards and manufacturer’s instructions.
Q6: What should I check before purchasing?
Verify the model label, one- or two-electrode configuration, supply voltage, terminal condition, approval markings, and physical condition. Request photographs of the actual item and confirm whether accessories or documentation are included.
Related GESTRA Equipment and Components
The following are related GESTRA level monitoring and boiler protection products. They are not all direct substitutes for the NRS 1-50.
- NRS 1-51 — Level Switch
- NRG 16-50 — Level Electrode
- NRG 17-50 — Level Electrode
- NRG 19-50 — Level Electrode
- NRG 111-50 — Level Electrode
- NRG 16-51 — Level Electrode
- NRG 17-51 — Level Electrode
- NRG 19-51 — Level Electrode
- NRG 111-51 — Level Electrode
- NRG 16-36 — Level Electrode
- NRG 1…-11 — Compatible electrode family for applicable versions
- NRS 2-50 — Boiler Level Monitoring Equipment
- NRR 2-50 — Level Controller
- NRR 2-51 — Level Controller
- SPECTORmodul — Boiler Level Monitoring System Family
Confirm the exact product code and system requirements before selecting related equipment for replacement.
Ordering Information
For quotation requests, specify GESTRA NRS 1-50 Level Switch, the required quantity, and the preferred stock condition.
Before ordering, confirm the required electrode configuration, power supply version, and applicable safety approvals. For boiler protection applications, installation, testing, and commissioning must follow the manufacturer’s instructions and relevant safety requirements.
