Marley Liquid Level Control Panels
Probe Type LLC Water Level Control
Overview
- Water Makeup
- High Water Alarm
- Low Water Alarm
- High Water Cutoff
- Low Water Cutoff
The most common application of a water level control system is water makeup. The system regulates the amount of water in the tower basin and keeps it within normal operating levels. This makeup system is used to control a remotely-installed water solenoid valve. When the water level drops below a prescribed, preset level, the solenoid valve is energized by the control system to fill the basin to its proper level.
High and low water alarms can be utilized to give warnings associated with abnormal operating water levels. The control system provides dry contacts to interface with various digital control systems or can be connected to user-supplied alarm indicators to signal when corrective action is required. Low-water cutoffs protect pumps from operating without sufficient water, preventing costly repairs.
Marley offers two types of water level controls:
Probe type systems which utilize relays operating in conjunction with stainless steel electrode probes mounted in a stilling chamber to monitor basin water levels, providing simple solenoid valve water makeup or discrete ON/OFF signals to more sophisticated automation controls.
Ultrasonic systems which utilize a non-contact ultrasonic sensor mounted on a stilling chamber.
Two systems are available:
- Standalone system used to control the makeup solenoid
- Stilling chamber
- Ultrasonic sensor
- Control panel with level relays and 4-20mA water level output
- Sensor only system when the BMS provides control and alarming
- Stilling chamber
- Ultrasonic sensor with 4-20mA output
These LLC systems may also be integrated into various Marley controls, including the Can Do panel, Single Point Power Connection (SPPC) panel, AIO (all in one) panel and Fluid Cooler Fan and Pump panels.
Probe Type Water Level Control for Cooling Tower Cold Water Basin
Cooling towers cool process water which flows to a cold water basin before being recirculated. A water level control system provides monitoring and control of water level in the cold water basin.
The Hanging Probe Type Water Level Control has one reference probe, two probes for water makeup (on, off), and one probe each for the following events: high alarm, high cutoff, low cutoff and low alarm. During manufacture, the LLC hanging probe panel can be configured for various combinations of water events.
Features:
- Relays provide simple solenoid valve water makeup or discrete ON/OFF signals to more sophisticated automation controls.
- Electrode probe tips are 303 stainless steel suspended from a noncorrosive PVC enclosure box with 30 feet of wire lead for each probe.
- A galvanized or stainless steel metal stilling chamber is installed over the probes to calm the water for accurate readings.
- Complete system includes the LLC control panel, hanging probe system with stilling chamber and a solenoid valve for water makeup.
- The control panel is UL/cUL listed.
Options:
- Optional configurations include water makeup along with high and low water level alarm and cutoff, or pump cutoff. Control systems including any of these variations are available.
Downloads:
Ultrasonic Liquid Level Control systems are used to accomplish five different functions:
- Water Makeup
- High Water Alarm
- Low Water Alarm
- High Water Cutoff
- Low Water Cutoff
The most common application of a water level control system is water makeup. The system regulates the amount of water in the tower basin and keeps it within normal operating levels. This makeup system is used to control a remotely-installed water solenoid valve. When the water level drops below a prescribed, preset level, the solenoid valve is energized by the control system to fill the basin to its proper level.
High and low water alarms can be utilized to give warnings associated with abnormal operating water levels. The control system provides dry contacts to interface with various digital control systems or can be connected to user-supplied alarm indicators to signal when corrective action is required. Low-water cutoffs protect pumps from operating without sufficient water, preventing costly repairs.
Features:
- Ultrasonic sensor located in a stilling chamber offers non-contact, precise monitoring cold water basin water level
- PLC (programmable logic controller) performs set point control and touchscreen provides visual of water level makeup set point and alarm set point.
- 120vac circuit powers remote water makeup solenoid valve.
- These circuits can be integrated into various Marley control panels, including the Can Do, SPPC, AIO and Fluid Cooler Fan and Pump panels.
OPTIONS:
Marley Ultrasonic Water Level Controls (LLC+u)
The Marley LLC+u water level control system consists of an ultrasonic sensor placed to measure the water level in the cold water basin. A programmable logic controller (PLC) with touch screen is used to program water level heights and offers a visual indication of the water level. Internal relays with form “C” contacts are used as switches, one for each water set point.
Marley LLC+u Engineering Data and Specifications
Comparison of Probe Type and Ultrasonic Water Level Controls
Marley Ultrasonic Integrated Water Level Controls (LLC+ui)
The Marley integrated LLC+ui control system is integrated into a larger Marley control panel along with other control circuits. The system is used to monitor, control and alarm water levels in the cooling tower cold-water basin via a non-contact ultrasonic sensor mounted on a stilling chamber. A PLC (programmable logic controller) performs set-point control and the color touch-screen provides a visual of the water level makeup set point and alarm set points.
Engineering Data & Specifications
Marley LLC+u+bms Ultrasonic Integrated Water Level Controls for BMS
The Marley LLC+u+bms control system is used to monitor water level in the cold water basin of a cooling tower cell using a non-contact ultrasonic sensor mounted on a stilling chamber. The sensor provides a 4-20mA continuous signal back to a BMS where alarming and controls are provided by the BMS.
