Associated Environmental Systems SD-302 Скачать руководство пользователя | Manualshive

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DESCRIPTION

2-3

A de-superheating expansion valve has been added to maintain acceptable suction gas
temperatures returning to the compressor when bypassing or when chamber pulls down from
high temperatures to low temperatures.

A pressure relief valve opens when the high side pressure goes above approximately 280 psig
and diverts the gas to the expansion tank.  The gas is returned to the low side of the system via a
restrictive tube.

Charging is by static pressure or weight if system is empty.  To check a static charge the unit
must not have been operated for at least 6 hours and have an ambient temperature of
approximately 70ºF.  Leaving system off, connect gauges and equalize pressure between high
and low side.  Optimum pressure should be between 100 psig and 125 psig.

R-404A-SYSTEM

When the mechanical refrigeration is switched on the R-404A compressor will start about 60
seconds before the SUVA-95 compressor to pre-cool the cascade and to minimize starting
current required for the chamber.  The R-404A system incorporates a hot gas bypass system to
“unload” the compressor during low or no load conditions.  Charging is done until the sight glass
is full.

Service Technician Please Note:  When the refrigeration system is bypassing hot gas, bubbles or
a low liquid level will appear in the sight glass.  This is normal and does not indicate an under
charged system.  Likewise, when charging system make sure hot gas is not bypassing, or the
system will be overcharged.  Bypass valve should be set to maintain 5-10 psig during no load
conditions.  Charging is done to full or near to full sight glass.

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Содержание SD-302

Страница 1: ...i c i a n sw i t ho v e r 1 5 0y e a r so f s p e c i a l i z a t i o n 9 0d a yw a r r a n t y 5d a yr i g h t o f r e t u r no na l l e q u i p me n t 1 3y e a r w a r r a n t i e sf o r n e wa n d p r e mi u m r e f u r b i s h e de q u i p me n t E v e r yu n i t t e s t e dt oO E Ms p e c i f i c a t i o n s S a t i s f a c t i o ng u a r a n t e e d Y o uh a v ep l a n s w ew i l l h e l py ...

Страница 2: ...CTION MANUAL INSTRUCTION MANUAL INSTRUCTION MANUAL MODEL SD 302 BENCHTOP TEMPERATURE CHAMBER Associated Environmental Systems 31 Willow Road Ayer MA 01432 Phone 978 772 0022 Fax 978 772 0088 http www associatedenvironmental com ...

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Страница 4: ...g 3 1 Placement 3 1 Power Requirements 3 1 Initial Inspection 3 3 IV Operation 4 1 Overview 4 1 Live Loads 4 2 Pilot Lights 4 3 Watlow PM Controller 4 4 Watlow F4 Temperature Controller 4 5 Overview 4 5 CO2 LN2 Boost 4 7 Dry Nitrogen Purge 4 8 Profile Programming 4 9 High Temperature Limit 4 14 High Low Temperature Safety Optional 4 15 V Maintenance 5 1 Cleaning CO2 5 2 Refrigeration System 5 3 Se...

Страница 5: ...or the fist time 6 1 Why does the chamber heat cool slower than specified 6 1 Should I put a filter in front of the air intake 6 1 How to Clean the chamber FAQ 6 1 Why is there ice or snow buildup in the chamber 6 1 Refrigeration System FAQ 6 2 Storage FAQ 6 2 Appendix A Parts List B Warranty C Wiring Print D Refrigeration Print E Controller Programmer Manual ...

Страница 6: ...quirements are 120V 1PH 60HZ These requirements are noted on the model nameplate located on the back of the chamber If a contradiction exists follow the power requirements on the nameplate The Programmer in your chamber has been set up and tested at the factory DO NOT change any parameters Disregard programmer instruction manual for setup procedures Contact factory before changing any settings Do ...

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Страница 8: ...ogrammer which features C F temperature control stability at the sensor Fast response nichrome type heaters on ceramic cores are used to raise the temperature and a two stage cascade mechanical refrigeration system lowers the temperature The chamber also has a high temperature failsafe to prevent the temperature from exceeding a preset limit The power requirements are 120V 1PH 60HZ These requireme...

Страница 9: ...necessary Never short or jump out heat links REFRIGERATION SYSTEM Cooling is accomplished by a cascade stage mechanical system using two 2 semi hermetic compressors Compressor utilizes polyester oil POE for lubrication The actual cascade is a brazed heat exchanger The low or SUVA 95 system removes the heat from the chamber and delivers it to the cascade in the form of high pressure gas The high or...

Страница 10: ...en high and low side Optimum pressure should be between 100 psig and 125 psig R 404A SYSTEM When the mechanical refrigeration is switched on the R 404A compressor will start about 60 seconds before the SUVA 95 compressor to pre cool the cascade and to minimize starting current required for the chamber The R 404A system incorporates a hot gas bypass system to unload the compressor during low or no ...

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Страница 12: ...mped on the model nameplate affixed to the rear of the chamber This is the correct requirement for the chamber and should be followed precisely in order for maximum efficiency and performance standards to be met The power must also include a positive earth ground to avoid any shock hazards ATTENTION Not all products from Associated Environmental Systems ship with a means of disconnect from the mai...

Страница 13: ...INSTALLATION 3 2 CHAMBER DRAIN Connect copper chamber drain in accordance with local codes It is located on the bottom rear of the chamber Copper Drain 5 16 ID 3 8 OD ...

Страница 14: ...ing Push heat and cool mechanical refrigeration switches on Confirm an increase in chamber temperature by observing the digital display As the chamber temperature approaches the set point the Heat pilot light will begin to flash indicating proper operation of the temperature control instrument at high temperatures STEP 3 The power heat and cool switches should all be on Set chamber temperature to ...

Страница 15: ...r LN2 or CO2 These capabilities are listed in the model nameplate Attach auxiliary system to connection on rear of chamber as indicated NOTE All auxiliary systems require an exhaust due to pressure being introduced into the chamber The exhaust port as indicated on the chamber must be open when using CO2 or LN2 ...

Страница 16: ...and cool mechanical refrigeration switches Setting the correct temperature before switching on the heat and cool switches prevents the chamber and your product from going to the previous set temperature while programming in the new one IMPORTANT ALWAYS CHECK THE FAIL SAFE LIMIT FOR PROPER PRODUCT PROTECTION To save energy wear and tear during operation the refrigeration system will shut off automa...

Страница 17: ...TION 4 2 LIVE LOADS The following data is an estimate actual chamber performance may vary SD 302 65 50W SD 308 40 500W SD 308 65 250W SD 405 10 500W SD 408 10 500W SD 502 37 75W SD 508 20 500W SD 508 37 200W ...

Страница 18: ...ion Flashing of the cool pilot light indicates that the chamber temperature is at or near the set temperature CO2 Optional When the CO2 pilot light is steady ON the chamber s optional CO2 cooling system is in operation Flashing of the CO2 pilot light indicates that the chamber temperature is at or near the set temperature LN2 Optional When the LN2 pilot light is steady on the chamber s optional LN...

Страница 19: ...eters See the temperature control setup page after the controller manual for the PID parameters QUICK USE Do not alter any parameters on the PM controller they have been preset Press the or button to the desired set point and push the heat or cool pilot light on the control panel SENSORS TEMPERATURE ONLY MODELS Uses 100 OHM at 0 C platinum resistance temperature detectors RTD based on the din curv...

Страница 20: ...of the F4 controller This is the actual temperature inside the chamber The units will be determined by the led located by F or C Lower display shows various information by pressing navigation key up or down and is used for changing set point or setup SP1 is the set point To change set point select SP1 by moving cursor up or down using navigation key up or down Press right arrow key to enter then p...

Страница 21: ...ture and RH 0 to 100 Temperature is read with line 1 and humidity is read with line 2 Recorder measures chamber temperature using its own 100 OHM platinum sensor independent of temperature controller Recorder receives electrical signal from controller that corresponds to chamber relative humidity dependent of temperature humidity controller HONEYWELL EZ TREND DIGITAL CHART RECORDER Touch screen re...

Страница 22: ...tions please check which option the chamber has before connecting the auxiliary cooling source Liquid CO2 using a 300 psi bulk type system Liquid CO2 using a 1000 psi siphon type liquid CO2 cylinder LN2 using 12 to 40 psi LN2 Close the chamber door and turn the POWER Circulation HEAT COOL and CO2 or LN2 Switches ON Using the controller establish the low temperature set point CO2 LN2 Boost is enabl...

Страница 23: ...o prevent a short circuit in electronic components and is also used to lower humidity within the chamber To use the dry nitrogen purge The chamber must have been ordered with the dry nitrogen system and connected to a GN2 source with a maximum pressure of 100 PSIG Close the chamber door and turn the PURGE Switch ON The Nitrogen Purge is enabled through Event 1 in profile programming Dry Nitrogen P...

Страница 24: ...sing Day of the week or Date Time Note To invoke an Autostart step in a profile you must activate the profile via the Profile Key and select the Autostart step Ramp Time Ramp Time changes the set point to a new value in a chosen period of time Ramp Time is the same for both channels of a dual channel controller Define the Ramp Time step by choosing Wait for an event or process value Wait for Event...

Страница 25: ...ed in the F4 s Profile Program memory the controller will terminate the profile and turn off all outputs if Continue Hold or Terminate was selected as the Power Out action If Profile Reset or Go to Idle Set Point was selected the controller will take those actions A pop up message will warn of this when the 21st jump step is programmed End End terminates the profile in a chosen state All profiles ...

Страница 26: ...rs See Step Types earlier in this section Choose Step1 Type __ Autostart Ramp Time Ramp Rate 5 Define each step type The Series F4 prompts you to define the parameters of each step type For example when you choose Ramp Time the Profile Guide asks if you want the step to wait for an event or process input before starting whether events outputs are on or off Choose to wait _____ Step does not wait S...

Страница 27: ...OPERATION 4 12 Sample Profile ...

Страница 28: ...s The cursor will be positioned on the current step type To keep it press and make your changes to the properties listed on succeeding screens If you choose to change a Step Type the Series F4 will prompt you to program all necessary parameters To insert a step Move the cursor to the number of the step that the new step will precede Press The Series F4 will prompt you to program all necessary para...

Страница 29: ...o quit programming or wait one minute and the display will automatically exit programming mode STEP 2 Close the door and turn the Power Circulation and Heat switches ON STEP 3 Set the primary controller temperature set point at the desired test temperature STEP 4 Allow the chamber to reach the set point and then wait 15 minutes for the system to stabilize itself at that temperature STEP 5 Reset th...

Страница 30: ...ss the green advance key to finish and return to the operations menu STEP 2 Close the door and turn the Power Circulation and Heat switches ON STEP 3 Set the primary controller temperature set point at the desired test temperature STEP 4 Allow the chamber to reach the set point and then wait 15 minutes for the system to stabilize itself at that temperature STEP 5 Reset the digital Failsafe control...

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Страница 32: ...MAINTENANCE 5 1 GENERAL MAINTENANCE TROUBLE ANALYSIS AND SERVICE GUIDE ...

Страница 33: ... will in effect bake out any residual frost or condensate which may tend to build up after running subfreezing temperature tests 5 Bearings of circulation motor are permanently lubricated No oiling is required Should the CO2 optional valve or nozzle become clogged clean as follows 1 Remove the solenoid valve and injection orifice assembly from the chamber 2 Clean the injection orifice with a fine ...

Страница 34: ...ow the unit to stand for one half hour With chamber empty close any ports or openings wipe out any moisture and close the door 3 Check condenser fin tubes in rear for possible restriction to airflow Clean with vacuum or compressed air if necessary or if water cooled check water flow to water cooled condenser 4 Set dry bulb control point at a temperature below ambient and turn on cool mechanical re...

Страница 35: ...e or fusetron 1b Defective refrigeration switch REMEDY Replace switch 1c Defective power relay in refrigeration circuit REMEDY Replace with equivalent relay 1d Off on high low or pressure if equipped cutout REMEDY Reset by pushing button on individual controls 2a Low line voltage or inadequate wiring REMEDY If voltage is low install booster transformer If voltage is low only when other loads draw ...

Страница 36: ...y out chamber Plug up port or any openings where room air can enter the chamber 1b Excessive live load in chamber or excessive heat leakage into chamber through ports or other openings REMEDY Eliminate cause 1c Excessive opening of door REMEDY Eliminate cause 1d Loss of refrigerant charge REMEDY Determine and repair leak and recharge system 1e Clogged or defective expansion valve REMEDY Repair or ...

Страница 37: ...an blade replace motor or repair as necessary 2d Temperature controller set point out of adjustment REMEDY Adjust in accordance with instruction manual 2e Condenser fan not running or not operating at rated rpm REMEDY Repair or replace condenser fan motor 2f Damaged or restricted refrigerant line REMEDY Locate and replace 2g Low voltage or worn relay contacts REMEDY Correct low volume condition or...

Страница 38: ... is normal 1c Condenser fan not operating properly REMEDY Tighten fan blade repair or replace the motor 1d Low line voltage REMEDY If voltage is inherently low install booster transformers If voltage is low only when other loads draw excessively connect chamber to another line which is not overloaded 1e Defective temperature controller REMEDY Repair temperature controller 1f Defective relay activa...

Страница 39: ...defective REMEDY Replace controller 1c Heat switch defective REMEDY Replace switch 1d Relay defective applies only for models having relays REMEDY Replace relay 1e Heater connection loose or heater defective REMEDY Check connection to heater or replace heater 1f Heat link open REMEDY Replace heat link do not attempt to repair and do not short it out 2a Heater connection broken REMEDY Correct conne...

Страница 40: ...ontroller 2a Defective Temperature controller REMEDY Replace controller 2b Defective relay applies only to models having relays REMEDY Replace relay 2c Heater shorted to ground REMEDY Determine ground and correct 1a Fan blade unbalanced or damaged REMEDY Add balance weights or replace fan blade 1b Fan motor shaft bent REMEDY Replace fan motor and blade 1c Fan shaft rubbing or fan blade hitting REM...

Страница 41: ... and provide ample running clearance 3a Area too small for the application or test piece improperly oriented REMEDY Larger chamber needed or rearrange test piece 1a Improper cleaning procedures corrosive materials generated by test piece rust deposited from ferrous material of test fixtures etc REMEDY The interior is a high alloy 18 chromium 8 nickel stainless steel which has extraordinary high re...

Страница 42: ...nly when operating below 100ºF 73 3ºC Some snow is always present in the range 75ºF to 100ºF but it melts as rapidly as it forms and does not accumulate sufficiently to affect temperature control 1a Temperature controller is out of calibration and the chamber temperature is actually below 100 F 73 3ºC REMEDY Calibrate controller ...

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Страница 44: ...in a manner that allows for air circulation The test sample should not occupy more than a third of the total working volume of the chamber You should not place the test sample directly on the chamber floor It should be placed on a shelf to ensure conditioning on all sides Multiple test samples should be positioned throughout the chamber to ensure even airflow If necessary additional shelves should...

Страница 45: ...ician who is familiar with low temperature refrigeration systems Please call Associated Environmental Systems to recommend a service company in your area Storage FAQ Before or after lengthy periods of inactivity the chamber should be inspected to ensure nothing has been damaged or a leak has not developed 1 Clean the interior and exterior of the unit 2 Check the refrigerant charge 3 Perform a visu...

Страница 46: ... ordering parts always include the model number and serial number of the chamber together with the description and part number of the replacement part needed Generally parts are shipped from stock within one day after receipt of purchase order Where design modifications or improvements change the part specification the up to date part can be furnished ...

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