SJE-Rhombus

LevCon™ Controller Specifications

Download LevCon™ Controller Engineering Specs Document (rtf format)

I. General
1.1 Scope Of Work
The contractor shall furnish, install and install a pump control system designed to operate two pumps in a sewage lift station as described herein. The control system shall be designed utilizing proven technology in control design for sewage lift stations. The control system shall be operator and maintenance friendly to ensure ease of system set up and to limit down time.

Model______ at ___HP, ___ Voltage, ___ full load amps ( FLA ), ___ single phase.

The control system shall use a submersible pressure transducer connected to an electronics liquid level indicator/controller mounted in a control panel.

The factory assembled system shall include:

These specifications describe model LevCon control panel as manufactured by SJE-Rhombus, Detroit Lakes , Minnesota , or approved equal.

II. Products
2.1 General
2.1.1 Codes
Electrical equipment, materials and workmanship shall comply with all applicable codes, safety and fire law regulations at the location of the work and shall conform to applicable codes and standards of the organizations listed below.

1. Institute of Electrical and Electronic Engineers. (IEEE)
2. National Electric Code. (NEC)
3. National Electrical Manufacturers Association (NEMA)
4. American National Standards Institute. (ANSI)
5. Underwriters Laboratories. (UL-508)
6. International Electrotechnical Commission (IEC)

2.1.2 Component Standards
All equipment and materials shall be new and shall bear the manufacturers name and trade name. In cases where the standard has been established for the particular material, the material shall be so labeled. The equipment to be furnished shall essentially be the standard product of a manufacturer regularly engaged in the production of the required type of equipment for this type of work and shall be the manufacturers latest approved design.

2.2 Construction
2.2.1 Enclosure
The described equipment shall be housed in a single NEMA 4X fiberglass enclosure. The enclosure minimum size shall be 28”high, 20” wide and 10” deep.

2.2.2  Heater
The enclosure shall be heated by a 50Watt anti-condensation heater controlled by a thermostat.

2.2.3 Control Circuit Wiring
Control circuit wiring inside the panel shall be 18 gauge (AWG) minimum, type MTW or THW, rated for 600 volts. All power wiring shall be rated for 600 volts. Conductors shall be color coded in the same colors throughout the entire panel.

All components shall be identified with a numerical or alphabetical reference. The component identification labels shall match the ones shown on the electrical schematics.

III. Components
3.1 LevCon™ Liquid Level Indicator/Controller
The set point level controller shall be a self-contained microprocessor controlled system capable of monitoring the level of the wet well and automatically controlling two pumps. The controller shall have 10 digital input channels, 1 analog input channel and 6 relay output channels. The controller shall be equipped with a keypad and a 2 line by16 character LCD display for level, pump status monitoring and operation setup. The controller shall be capable automatic alternation and auto reversing two pumps and of monitoring low level, high level pump run status, pump seal failure and pump over-temperature. The level controller shall also be capable of wet well level simulation and of logging run time and cycles for each pump. The controller shall be UL listed.

3.1.1 Analog Input
The controller shall come standard with a 4-20mA input channel. The input shall be scalable from 0 to 999 and the measurement unit shall Inches (In). The controller shall detect invalid sensor readings and open loop circuit and display a fault message and de-energize the relay outputs. The analog input channel shall have a 0.1% resolution and incorporate noise filtering and averaging

3.1.2 Digital Inputs
The controller shall come standard with 10 input channels.

3.1.3 Relay Outputs
The controller shall come standard with 6 relay outputs, each output capable of switching 5A at 250 VAC.

3.1.4 Level Set Points
The pump operation and alarm status shall be dependent on the following level set point in the controller:

Level adjustments shall be accomplished via the front keypad without the use of tools, laptop computer or extensive configuration.

3.1.5 Display/Keypad
The controller shall allow the user to navigate through the configuration mode and adjust set point values via the front keypad. The controller setup shall be simple and shall not require the use of a laptop computer. A simulation mode shall be available for users to manually increase or decrease the level value from the keypad as to test the relay output sequence operation. The simulation mode shall end automatically when the user releases the keypad buttons and the actual level monitoring is resumed.

3.1.6 Power
The controller shall require 12 VDC for proper operation and shall be battery backed up. A power supply / battery charger shall convert 110VAC to 12VDC and supply power to the controller and charge the gel cell batteries. Such power supply shall be approved, registered and /or certified by the Underwriter Laboratory (UL).

3.1.78 Manufacturer
The level controller shall be as manufacturered by SJE-Rhombus, model LevCon™.

3.2 Submersible Transducer Level Control
The level transducer shall use an isolated diaphragm sensor, which is specifically designed for use with hostile fluids and gasses. The sensor element shall utilize a block of piezoresistive silicone with a stainless steel barrier diaphragm. The sensor shall be housed in a 316 stainless steel case. The static accuracy of this equipment shall be better than 1% of full scale. The level transducer shall be two wire loop powered and produce a 4-20mA proportional to the wet well level and be fully temperature compensated. The transducer shall be suspended within a 4" PVC stilling tube attached to the basin with stainless steel anchors. The transducer shall be wired to the pump station control panel termination point using one continuous vented cord (no splices allowed) and shall not be in the same conduit as the pump cables.

3.3 Back Up Float Switches
Two back up float switches shall be provided with each control system. A high level float to activate the beacon and horn and a low level float to prevent the pumps to run dry. The high level alarm float shall be directly connected to the alarm circuitry and the low level float shall disengage the motor starters in the down position (open circuit). Each float switch shall be wired to the pump station control panel termination point using one continuous cord (no splices allowed) and shall not be in the same conduit as the pump cables. The floats switches shall be as Manufactured by SJE-Rhombus model Sensor Float® or approved equal.

3.4 Modem Communication
Each control panel shall be equipped with a dial up modem connected to the LevCon via its RS232 communication port. The modem shall be connected to a phone line and dial out to the central computer at the Waste Water Treatment plant after a predetermined period or in the event of an alarm condition. The controller and modem shall be well immune from electrical noise and poor phone line quality and shall still perform its monitoring, control and communication tasks. The modem shall connect to a standard analog 2-wire telephone line; no leased or dedicated lines shall be required.

3.5 Data Logging
The controller shall also log data between the call out period (cycle counts, daily cycle counts, total hours run, daily total hours run, total lag pump operation cycles, daily total lag pump operation cycles, total high level counts and daily total high level counts.

3.6 Seal Fail Monitoring
Seals Failure relays providing adjustable resistance sensing circuitry from 0 to 250,000 ohms shall be provided to monitor the seal integrity of each pump. Upon activation, the seal failure relay an alarm message shall be displayed on the screen of the LevCon™ controller. The moisture sensing probes shall be supplied and installed in the pumps by the pump manufacturer.

3.7 Over Temperature Monitoring
Pump over temperature sensors located in the pump motor shall be supplied for each pump. A pump high temperature condition shall trigger an alarm message on the LevCon™ controller display.

3.8 Grinder Station Control System Base Computer
For the lump sum bid, the CONTRACTOR shall furnish and install a base computer which shall be able to remotely monitor and control all residential grinder pump stations within the system. The base computer shall be of the desk top design, of new construction and shall include the following as a minimum:

The modem shall connect to a standard analog 2-wire telephone line; no leased or dedicated lines shall be required. The base computer shall be installed in the location designated by the OWNER.

3.9 SCADA Software
The service personnel shall be notified via modem communication of any failure at any grinder stations, and shall be able visualize real time status of the pumps, wet well level and data log. This data must be printable on an ink jet printer. These screens shall also be saved as files on the hard drive. The computer must be able to connect up to 500 remote stations. The software shall be pre-installed on the desktop computer and tested by the SJE-Rhombus prior to delivery.

3.10 Control Panel Standard Features
The following devices shall be included as standard features with each control system:

- LevCon™ Indicator/Controller
- Pump run indication
- Pump seal fail indication
- Back up float status indication
- Run time meters
- Cycle counters
- Fault reset button
- Pump alternation
- Lead pump selector (1, 2-Alt-2, 1)
- Level simulation
- Modem for remote dial up communication
- Battery back up for controller/transducer and modem
- (2) Motor starters (IEC)
- (2) Hand-Off-Auto selector switches
- (2) Moisture detection modules (seal fail)
- Alarm Test/Normal/Silence switch
- Alarm beacon and horn
- Space heater to prevent condensation within the enclosure
- Lightning arrestor
- Serialized UL-508 label

3.12 Circuit Breakers
All electrical circuits shall be protected by molded case circuit breakers. Each pole of the breaker shall provide inverse time delay overload protection and instantaneous short circuit protection by means of a thermal magnetic element.

The breaker shall be operated by a toggle-type handle and shall have a quick make, quick break switching mechanism that is mechanically trip free from the handle. Tripping due to overload or short circuit shall be clearly indicated by the handle automatically assuming a position midway between the manual “on” and “off” position. Breakers shall be completely enclosed in a molded case and shall bear the UL label.

3.13 Motor Starters
All starters shall be full-voltage reversing IECstyle and bear a UL label. The coil operating voltage shall be 120 volts AC 60 Hz. The starters shall not require the use of ambient compensated overload relays.

3.14 Relays
3.7.1 Relay Type
Relays shall be of the square base plug in type with integral LED indicator lights. All relays shall have a transparent polycarbonate dust cover to protect the contact surfaces from airborne dust and other contaminants. All relays shall have DPDT or 4PDT contacts, as required. Relays shall be rated for continuous duty operation.

3.7.2 Relay Contacts
Relay contacts shall be rated for 10 amps at 300VAC. Relay sockets shall have screw terminals with self-lifting clamps and terminal identification numbers located at each connection on the relay socket.

3.15 Lightning Arrestor/Surge Arrestor
A lighting/surge arrestor shall be provided at the incoming power terminals to the control panel. The unit shall be of the solid state type and be able to clamp in five (5) nanoseconds and absorb up to 25KA peak surge current during an occurrence. The unit shall have a surge life expectancy of 10,000 occurrences at 200 amps.

3.16 Alarms
High Level Alarm beacon and a horn shall be included with a test/normal/silence switch. On decreasing levels, the alarm condition will automatically reset when the level falls below the high level alarm set point.

IV. Quality Assurance
4.1 Manufacturer Experience
4.1.1. UL Certification
The manufacturer of the control system shall be certified by Underwriters Laboratories (UL) as being a UL 508 Listed manufacturing facility and certified to install a serialized label for quality control and insurance liability considerations.

4.1.2 Experience
The manufacturer of the control system must be able to document ten years of experience in successfully designing and manufacturing similar control systems for wastewater pumping applications.

4.2 Manufacturer Quality Control
The complete control system shall be functionally tested at the manufacturing facility and certified as a complete system to assure proper operation per specification.

4.3 Manufacturer Approval
Manufacturers listed in this specification do not constitute approval. All controls must have the capabilities and functions as outlined in the specifications.

V. Submittal Requirements
5.1 Base Bid
The base bid control system shall be the LevCon™ control system as manufactured by SJE-Rhombus, Detroit Lakes Minnesota. Contract shall be awarded on the base bid control system. Alternative deductive systems will be considered only after contract award and must be specified with any applicable deducts at bid time in order to receive consideration. Bidders submitting alternate quotations shall submit appropriate cut sheets, circuit drawings and a detailed bill of materials with their alternate bid packages. Approval of an alternative system shall be at the sole discretion of the engineer. All equipment and materials shall be new and shall be specifically designed for the function herein.

5.2 Substitutions
The Engineer will consider proposals for substitution of materials, equipment, methods and services only when proposals are accompanied by full and technical data and all other information required by the Engineer for the proposed substitution. Substitution of materials, equipment, methods and/or services is not allowed unless such substitution has been specifically approved by the Engineer.

5.3 Shop Drawing Submittals
5.3.1 Drawing Requirements
All drawings are to be of the computer generated class.

5.3.2 Engineering Approval
The Engineer reserves the right to approve or disapprove any and all equipment during the evaluation process. Approval for fabrication and installation will be made only after submittal and review of all shop contract documents. The information required for approval shall include the following items and be provided in (8) sets as a minimum: