Product Information:

Cascade EWS System Overview

Alarm Outputs

Monitor & Accessories

Product Pricing & Availability

Typical Applications

Product Limitations

Detect Maintenance Problems Early

Electrical Approvals

Sensor Inputs

Warranty & Satisfaction Guarantee


Cascade EWS System Overview:

The Cascade Early Warning System (EWS) is a multi-function Heating, Ventilation, Air Conditioning, Refrigeration and pumping system monitor. The primary function of the EWS is to measure and analyze the operating current of electrical motor loads like compressors, pumps, fans, and heaters and lighting circuits to provide an Early Warning of possible System failure.

The main design criteria for the EWS was to provide a comprehensive yet inexpensive monitor system that could warn of a pending problem before more serious damage is caused to equipment, facilities, or product. The system was to be easy and inexpensive to install, would be operator friendly and would be self-calibrating. The system would provide useful information to make the job of a system maintenance technician easier.

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Monitor & Accessories: Photos & Technical Information

EWS-MP Monitor Panel, hardware Version 3, Firmware Version 3.1

EWS-CT three phase Current Transformer

EWS-CT1 single phase Current Transformer

EWS-TS integrated circuit Temperature Sensor

EWS-SW Switch sensor with target magnet

EWS-ML Minimum Load, 120mA at 120V 60hz.

EWS-RA Remote Alarm, 12Vdc, 12mA

EWS-PA Power Adaptor 120Vac to 12Vdc

 EWS-DL Data Logger with 4 days memory

EWS-DV Data Viewer Version 1.1

EWS-IM Interface Module to provide a 0 - 5 Volt outputs from an EWS-CT

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Typical Applications:

Typical Applications for the EWS monitor system include most applications where an electric motor is used including:

-  retail convenience stores that have refrigerated chests and cabinets,

-  restaurant and food preparation facilities with freezers and refrigerated spaces, exhaust and makeup fans,

-  commercial warehouse and processing facilities with coolers, chillers, and mechanical refrigeration, bulk material handling systems, conveyor systems,

-  recreation facilities including ice rinks, swimming pools, and hot tubs,

-  agricultural production and storage facilities including confined livestock ventilation, heating, and watering, fish farm water circulation and temperature controls, vegetable and fruit storage, grain and material handling conveyors, augers, legs, feed processing, grinding and mixing, grain and forage drying, water heating / cooling systems, potable water systems, and

-  industrial installations including circulation pumps, oil field production pumps, driers and separators, compressor stations, and chemical production and processing facilities.

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Detect Maintenance Problems Early:

There are some maintenance issues that can cause equipment damage or abnormal power consumption that can be detected by monitoring the load current. Situations that can cause equipment failure that can sometimes be detected by current monitoring include:

-  condenser is plugged with tree fluff or leaves, condenser fan fails to come ON or thermostatic two speed fan switch fails may cause excessive head pressure, higher compressor running current and longer run times.

-  compressor seals begin to leak and lubricant is lost causing excessive running current and higher starting currents.

-  slow leak of refrigeration fluid causes excessive ON times and lower operating current than normal.

-  worn compressor may cause abnormal running current, higher starting currents, and longer run times.

-  faulty defrost cycle, faulty evaporator fan(s), or a frozen evaporator can cause lower running current, excessive compressor cycling, or longer run times.

-  plugged air filters can cause abnormal fan motor current.

-  plugged in-line filters can reduce pump efficiency and affect system pressures and flow rates.

-  faulty dampers can cause abnormal fan motor currents and run times.

-  faulty heaters can cause abnormal process temperatures or equipment freeze-up.

-  faulty fans or circulation pumps can cause abnormal process temperatures.

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Sensor Inputs: Current, Temperature, Switch contact

The EWS Monitor Panel (EWS-MP) has three types of Sensor Inputs and four Alarm Outputs. The Sensor Inputs are as follows:
  1. four channels of 3 phase current monitoring (or up to 12 channels of single phase current monitoring)

The primary function of the EWS is to measure and analyze the operating current of electrical loads like motors, compressors, fans, heaters and lighting circuits. A current sensor (called a Current Transformer) is installed to measure the current used by an electrical load.

The EWS-MP is able to provide a very wide range of current monitoring by using a non-linear burden on the current transformers. The voltage signal produced when the CT is connected to the MP provides sensing of load currents from 0.01 to 100 amps. The resolution of the current measurement is about 20 points per decade of current which is adequate for general purpose load monitoring.
  1. four channels of temperature monitoring ( -50C to +80C )

Most mechanical systems in buildings and processes attempt to control or maintain a process temperature. A secondary function of the EWS is to monitor process temperature and provide a warning if the temperature fluctuates more than desired.

  1. one channel of general purpose timed switch contact input.
Any number of switch type sensors can be connected in series or parallel to provide a normally closed circuit.
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Alarm Outputs: Temperature, Circuit Breaker, Current, and Switch

There are four types of alarms generated. They are categorized according to their potential severity and the response time required to take remedial action.
    1. The most serious alarm would occur if the process temperature is out of range because damage to product or the process may be about to happen. The temperature is checked against the value determined during calibration to be "normal" every 10 seconds. If the temperature has drifted beyond the limit selected, then the local audio alarm is sounded and the appropriate channel and alarm indicator comes ON blinking.
    2. The second most serious condition might be a circuit breaker trip. This may not immediately be cause for concern but the process will gradually drift out of specification soon after. A circuit breaker trip is detected and an alarm is generated within two minutes.
    3. The switch input is expecting an normally closed circuit. If the circuit is open continuously for more than 5 minutes then an alarm is generated. The switch input is typically used to monitor if the doors on freezer cabinets are closed. If the doors are left open too long, then the temperature distribution within the cabinet will be disturbed and damage to product will eventually occur.
    4. The average running current, peak starting current, and running duty cycle alarms are combined into a single alarm output. These conditions are averaged over a 24 hour period and if an abnormality is detected at the end of the 24 hour period, an alarm is generated. Changes in these parameters generally occur slowly over a period of days or weeks and when the accumulated change from when the system was calibrated is significant, an alarm is generated.
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Limitations to consider:

Note that there are some limitations to the features and applications of the EWS Monitor Panel:
-  The EWS is not to be used for life-critical or life-support applications.

-  The EWS is not intended to replace or over-ride control systems or limit devices that are required for safety purposes.

-  Cascade does not provide the alarm monitoring system that may have an auto dialer and remote monitoring. Most facilities have a security alarm system that can be connected to the EWS-MP to provide that service.

-  The EWS-CT Current Transformers are for measuring 50 or 60 hz Alternating Current only.

-  If a load is running continuously, then the duty cycle monitoring is meaningless and this feature can be disabled using a programming switch setting.

-  If a load is continuously variable or has stepped or staged loads that change over a wide range, (such as a variable speed motor drive or a two speed fan) then the average running current limits are meaningless and this feature can be disabled using a programming switch setting.

-  If a load changes significantly with seasonal variations, then seasonal re-calibration may be required to minimize false alarms.

-  If the load current is zero when the load is switched OFF, then the breaker trip monitoring is not functional. An optional accessory, the EWS-ML Minimum Load device can be used to provide a minimum pilot current for circuit breaker trip detection.

-  The range of the standard temperature sensor is from -50C to +60C.

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Electrical Approvals: CSA / NRTL

The EWS system is CSA / NRTL approved as a Class 2 monitoring system when operated from a Class 2 power source. This makes installation of sensors and wiring in non-hazardous areas as simple and inexpensive as possible. Of course, sensors and wiring should be mechanically protected from damage so that the monitor system will operate reliably.

The EWS-CT Current Transformers are CSA / NRTL approved as a Class 1 to Class 2 interface device. The CT is mounted in a knockout of a junction box or electrical equipment panel with the Class 1 circuits inside and the Class 2 circuit outside.

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Product Availability, Pricing and Technical Support:

Contact Cascade Systems for technical support, a local distributor / dealer or to place an order directly with Cascade.
Cascade Systems Inc.
c/o Concepts To Market
Edmonton, AB, Canada
Tel: (780) 413-4285
Fax: (780) 438-5201

The end-user pricing of the EWS components is given below in US$ and CDN$. Quantity discounts are available for distributors and installers. Contact Cascade Systems for information about distributing these products. Shipping costs via UPS ground are included for system purchases. Shipping costs for individual components or for other shipping methods will be to the purchasers account.




EWS-SK System Kit includes 1 EWS-MP, 1 EWS-CT, 1 EWS-TS, 1 EWS-PS



EWS-MP Monitor Panel, hardware Version 4, Firmware Version 4.1



EWS-CT three phase Current Transformer



EWS-CT1 single phase Current Transformer



EWS-TS integrated circuit Temperature Sensor



EWS-SW Switch sensor with target magnet (pack of 5)



EWS-ML Minimum Load, 120mA at 120V 60hz.



EWS-WP 100 ft sensor extension wire kit  $5.74 $8.62

EWS-RA Remote Alarm, 12Vdc, 12mA



EWS-PS Power Supply Adaptor 120Vac to 12Vdc



EWS-DL Data Logger with 4 days memory $300.00 $450.00
EWS-DV Data Viewer Version 1.1 $68.00 $100.00
Firmware upgrades for EWS-MP and EWS-DV when available (call for current versions and upgrade pricing)    
EWS-IM Interface Module to provide a 0 - 5 Volt outputs from an EWS-CT that can be used as an input signal to a Programmable Logic Controller. The output voltage is a linear conversion of the rms value of the measured load current. There are ranges available for 10, 20, 50, and 100 amps full scale. $300 $400

Due to our policy of continuous product enhancement and to provide great value to our customers, specifications and prices are subject to change without notice.

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Warranty and Satisfaction Guarantee:

Cascade Systems Inc. warrants that any manufacturing defect found within two years of installation of the monitor or sensors will be repaired at no cost for labor or materials. A defective unit must be returned to Cascade Systems Inc. or an authorized service center for warranty repair.

If you install a Cascade EWS and, after contacting Cascade Technical Support, the system is found to be not suitable for your application, then Cascade Technical Support will issue a Return Authorization Number and the components can be returned directly to Cascade for a full refund of your purchase price.

There is no warranty as to the fitness or function of the monitor system with respect to any particular application. In no circumstances will Cascade Systems be liable for any subsequent or consequential damages arising from the use or misuse of this product.

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