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This advanced function control system by MCS Controls is designed to maintain suction superheat and adapt to changing conditions. It features specialized startup functions, fast zone hold capabilities, and EXV delay functions. The system requirements include specific software and firmware versions. The valve startup functions include basic, quick, hold, normal, and long settings, providing precise control over the system. The fast zone hold function defines steady state and adjusts suction superheat accordingly. Additionally, the fast zone delay function allows for optimized system adjustments. For more details, visit www.mcscontrols.com or contact MCS at 239-694-0089.
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Designed to Maintain Suction Superheat and Anticipate Changing Conditions (Advanced Functions) MCS FAST SSH www.mcscontrols.com Revised 1.0 -December 20, 2019
Design Criteria • Specialized Startup functions • Specialized Fast Zone Hold function • Specialized EXV Delay functions • Projected Fast Suction Superheat Degrees C
System Requirements 1. Requires MCS-Config Version 18.00V or greater. 2. Requires MCS-Connect Version 18.10.09 or greater. 3. Requires Magnum HVAC/RTU firmware Ver. 17.25K hex or greater. 4. Requires Config Type 17.
Specialized Valve Startup FUNCTIONS BASIC DESCRIPTION EXV TME LONG EXV TME QUICK EXV TME HOLD EXV TME NORMAL SP 19 EXV STARTUP TIME = 90 SECONDS SP 9 11.0 TARGET SP 10 ± 2 FAST ZONE (RED LINES) EXV HOLD CALCULATED 0 to 39 SECONDS (VER 17.25K) EXV QUICK CALCULATED 40 to 60 SECONDS (VER 17.25K) SP 19 90 SECONDS EXV STARTUP (VER 17.25K)
Specialized Valve Startup FUNCTIONS (cont) BASIC STARTUP EXV TME QUICK EXV TME HOLD EX TME NORMAL EXV TME LONG SH < TARG + 5 TAKE CTL & NO CHG VLV% HOLD EXV STARTUP SH > TARG + 5 TAKE CTL & INCR VLV% BY 1.0 SH < TARG + 5 TAKE CTL & DECR VLV% BY 1.0
Specialized Valve Startup FUNCTIONS (cont) CONTROL TOO FAST, CONTROL CORRECT, CONTROL TOO SLOW EXV TME QUICK EXV TME HOLD EXV > HI TME & < LO TME EXV TME LONG SH > TARG + 15.0 & ROC > 0 TAKE CTL & INCR VLV% BY 1.0 HOLD EXV STARTUP PROTECTS VALVE FOR OPENING SET TOO SMALL TEST BEGINS AT END HOLD TIME SH > TARGET + 15.0 DEGREES AND GETTING LARGER
Specialized Valve Startup FUNCTIONS (cont) PROTECTS AGAINST LOW SUPERHEAT DURING STARTUP EXV TME HOLD EXV > WAIT TME & < LONG TME EXV TME LONG SH < LOW SH SP & ROC < 0 TAKE CTL & DECR VLV% BY 2.0 HOLD EXV STARTUP PROTECTS VALVE IF OPENING TOO LARGE TEST STARTS AT END OF HOLD TIME SH < LOW SUPERHEAT SP AND ROC < 0
Specialized Valve Startup FUNCTIONS (cont) PROTECTS AGAINST LOW SUCTION PSI DURING STARTUP EXV TME HOLD EXV > HOLD TME & < LONG TME EXV TME LONG SUCT PSI < LOW SUCT SP & SH > TARG – FAST ZN TAKE CTL & INCR VLV & BY 2.0 HOLD EXV STARTUP PROTECTS VALVE IF OPENING TOO SMALL TEST BEGINS AT END OF HOLD TIME SUCTION PSI < LOW SUCTION SP BUT SH IS ABOVE LOWER LIMIT FAST ZONE TAKE CTL AND INCR VALVE STARTING % BY 2.0
Specialized Fast Zone Hold function DEFINES STEADY STATE AND WHERE SP 10 USES MPLY IF REQUESTED FAST ZN + SH ADJUSTMENT MPLY SP 10 TIME FIELD SH = TARGET ± (FAST ZN / 2) ROC = 0 TARGET SH = TARGET ±(FAST ZN / 10) ROC = 0 OR ± .1 SH = TARGET ± (FAST ZN / 2) ROC = 0 SH ADJUSTMENT MPLY SP 10 TIME FIELD FAST ZN -
Specialized Fast Zone Delay function • SP 19 DEFINES DELAY TIME WHEN EVALUATING EXV IN FAST SUPERHEAT • FOR FAST SUCTION SUPERHEAT • USUALLY 1 • IF GREATER THAN 1 USED, IT IS ONLY USED WHEN WITHIN FAST ZONE • IF OUTSIDE FAST ZONE SYSTEM DEFAULTS TO 1 • FOR FAST DISCHARGE, EVAPORATOR LEVEL SENSOR OR DX RTU • WILL NEED TO BE LARGER DUE TO SLOWER REACTION TIME • WHEN WITHIN FAST ZONE SYSTEM USES VALUE SPECIFIED SP 19 • WHEN OUTSIDE FAST ZONE, BUT LESS THAN 2 TIMES FAST ZONE • EXV DELAY TIME IS DIVIDED BY 2 • WHEN OUTSIDE FAST ZONE BY MORE THAN 2 TIMES • EXV DELAY TIME IS DIVIDED BY 4
Specialized Fast Zone Hold function DEFINES EXV DELAY TIME WHEN VALUE 4 OR GREATER EXV DELAY = SP VALUE / 4 EXV DELAY = 15 FAST ZONE 3 FAST ZN + EXV DELAY = 30 EXV DELAY = SP VALUE / 2 FAST ZONE 2 FAST ZN + FAST ZONE 1 EXV DELAY = 60 EXV DELAY = SP VALUE TARGET FAST ZONE 1 FAST ZN - EXV DELAY = 30 EXV DELAY = SP VALUE / 2 FAST ZONE 2 FAST ZN - EXV DELAY = SP VALUE / 4 EXV DELAY = 15 FAST ZONE 3 ASSUMING CONTROL IS BASED ON LIQUID LEVEL SENSOR & SP 19 (EXV DELY = 60 SEC)
Fast Suction SH F / PSI Setup SP 9 FAST SH TRGT 11.0 DEGREES F SP 10 FAST SH ZONE 2.0 DEGREES F SP 14 LIMIT ADJUST 0.3 PERCENT & 1.5 PERCENT (ASSUMED DECIMAL 1.5) SP 18 LO SUPERHEAT 2.0 DEGREES F
Fast Suction SH C / BARS Setup SP 9 FAST SH TRGT 6.0 DEGREES C SP 10 FAST SH ZONE 1.2 DEGREES C SP 14 LIMIT ADJUST 0.2 PERCENT & 1.5 PERCENT (ASSUMED DECIMAL 1.5) SP 18 LO SUPERHEAT 1.0 DEGREES C
Fast LEVEL SH Setup SP 9 FAST LVL TRGT 35 PERCENT SP 10 FAST SH ZONE 2.0 PERCENT SP 14 LIMIT ADJUST 0.2 PERCENT & 1.5 PERCENT (ASSUMED DECIMAL 1.5) SP 18 LO SUPERHEAT 1.0 DEGREES C
MCS FAST SUPERHEAT For additional information please visit our website www.mcscontrols.com Application Note 116 (Support, Literature, App Notes) Or call MCS at 239-694-0089 5580 Enterprise Pkwy. Fort Myers, FL 33905 Office: 239-694-0089 Fax: 239-694-0031 www.mcscontrols.com