Carrier aquazone 50RTG Installation, Start-up And Service Instructions Manual

Contents

Carrier aquazone 50RTG Installation, Start-up And Service Instructions Manual Manual pdf 14 page image

14Step 8 — Low Voltage WiringTHERMOSTAT CONNECTIONS — The thermostat shouldbe wired directly to the Aquazone™ control board. SeeFig. 4 and 5.WATER FREEZE PROTECTION — The Aquazone controlallows the field selection of source fluid freeze protectionpoints through jumpers. The factory setting of jumper JW3(FP1) is set for water at 30 F. In earth loop applications, jumperJW3 should be clipped to change the setting to 13 F whenusing antifreeze in colder earth loop applications. See Fig. 6.AIR COIL FREEZE PROTECTION — The air coil freezeprotection jumper JW2 (FP2) is factory set for 30 F and shouldnot need adjusting, unless using anti-freeze.ACCESSORY CONNECTIONS — Terminal labeled A onthe control is provided to control accessory devices such aswater valves, electronic air cleaners, humidifiers, etc. This sig-nal operates with the compressor terminal. See Fig. 7. Refer tothe specific unit wiring schematic for details.NOTE: The A terminal should only be used with 24 voltsignals — not line voltage signals.WATER SOLENOID VALVES — Water solenoid valves maybe used on primary secondary pump and ground water installa-tions. A typical well water control valve wiring which canlimit waste water in a lockout condition is shown in Fig. 7. Aslow closing valve may be required to prevent water hammer.When using a slow closing valve, special wiring conditionsneed to be considered. The valve takes approximately 60 sec-onds to open (very little water will flow before 45 seconds) andit activates the compressor only after the valve is completelyopened by closing its end switch. When wired as shown, thevalve will have the following operating characteristics:1. Remain open during a lockout.2. Draw approximately 25 to 35 VA through the “Y” signalof the thermostat. PRE-START-UPSystem Checkout — When the installation is completeand the system is cleaned and flushed, follow the SystemCheckout procedure outlined below.1. Voltage: Ensure that the voltage is within the utilizationrange specifications of the unit compressor and fan motor.2. System Water Temperature: Ensure that the systemwater temperature is within an acceptable range to facili-tate start-up. (When conducting this check, also verifyproper heating and cooling set points.)3. System Water pH: Verify system water acidity(pH = 7.5 or 8.5). Proper pH promotes the longevity ofhoses and heat exchangers.4. System Flushing: Properly clean and flush the systemperiodically. Ensure that all supply and return hoses areconnected end-to-end to facilitate system flushing andprevent fouling of the heat exchanger by system water.Water used in the system must be potable and should notcontain dirt, piping slag, and chemical cleaning agents.5. Closed-Type Cooling Tower or Open Tower with HeatExchanger: Check equipment for proper temperature setpoints and operation.6. Verify Balanced Water Flow Rate to Heat Pump.7. Standby Pump: Verify that the standby pump is properlyinstalled and in operating condition.8. Access Panels: Assure that all access panels in the filterand fan section are securely closed.9. Air Dampers: Assure that all air dampers are properlyset.IMPORTANT: This can overheat the anticipators ofelectromechanical thermostats. Only use relay basedelectronic thermostats.CapacitorCirc BrkrGrndContactor-CCL2 L1TransformerCBAquazone “C”See NoteLow VoltageConnectorTHERMOSTATWIRED DIRECTLYTO CONTROLBOARDBRNOTE: Low voltage connector may be removed for easy installation.Fig. 5 — Low Voltage Field WiringTypicalWaterValveCA24 VACTerminal Strip P2AQUAZONE CONTROL (C Control Shown)Fig. 6 — Typical Aquazone Control BoardJumper LocationsFig. 7 — Typical D Control Accessory Wiring