Carrier AQUASNAP AIR COOLED CHILLERS WITH COMFORTLINK CONTROLS 30RAP010-060 Operation And Service Manual

Also see for Aquasnap 30RAP010: Installation instructions Start up & operation manual Product data Product data

Carrier AQUASNAP AIR COOLED CHILLERS WITH COMFORTLINK CONTROLS 30RAP010-060 Operation And Service Manual Manual pdf 43 page image

43DEMAND LIMIT (CCN Loadshed Controlled) — To con-figure Demand Limit for CCN Loadshed control set the De-mand Limit Select (ConfigurationRSETDMDC) to 3.Then configure the Loadshed Group Number (Configura-tionRSETSHNM), Loadshed Demand Delta (Configu-rationRSETSHDL), and Maximum Loadshed Time(ConfigurationRSETSHTM). See Table 27.The Loadshed Group number is established by the CCNsystem designer. The ComfortLink controls will respond to aRedline command from the Loadshed control. When theRedline command is received, the current stage of capacity isset to the maximum stages available. Should the loadshed con-trol send a Loadshed command, the ComfortLink controls willreduce the current stages by the value entered for LoadshedDemand delta. The Maximum Loadshed Time is the maximumlength of time that a loadshed condition is allowed to exist. Thecontrol will disable the Redline/Loadshed command if noCancel command has been received within the configuredmaximum loadshed time limit.Cooling Set Point (4 to 20 mA) — A field suppliedand generated, externally powered 4 to 20 mA signal can beused to provide the leaving fluid temperature set point. Connectthe signal to LVT7,8 (+,–). See Table 27 for instructions toenable the function. Figure 22 shows how the 4 to 20 mA sig-nal is linearly calculated on an overall 10 F to 80 F range forfluid types (ConfigurationOPT1FLUD) 1 or 2. The setpoint will be limited by the fluid (FLUD) type. Be sure that thechilled water loop is protected at the lowest temperature.50% CAPACITY AT 20 mA75% CAPACITY AT 12 mA100% CAPACITY AT 4 mA0 2 4 6 8 10 12 14 16 18 20DEMAND LIMIT SIGNAL – 4 - 20 mA INPUT100806040200MAX. ALLOWABLE LOAD (%)Fig. 21 — 4 to 20-mA Demand Limiting100(38)80(27)60(15)40(4.4)20(-7)0(-17)4 6.3 8.6 10.9 13.1 15.4 17.7 204 TO 20 mA SIGNAL TO EMMSET POINT, F (C)90(32)70(21)50(10)30(-1)10(-12)(FLUD = 2) MINIMUMSET POINT 14 F (-10 C)(FLUD = 1) MINIMUMSET POINT 38 F (3.3 C)MAXIMUMSET POINT70 F (21.1 C)Fig. 22 — Cooling Set Point (4 to 20 mA)EMM — Energy Management Module