York YMB SERIES Installation Manual

Also see for YMB SERIES: User's information manual

Contents

York YMB SERIES Installation Manual Manual pdf 6 page image

361813-UIM-A-02086 Unitary Products GroupFIELD CONNECTIONS POWER WIRING1. Install the proper size weatherproof disconnect switch outdoorsand within sight of the unit.2. Remove the screws at the bottom of the corner cover. Slide cornercover down and remove from unit. See Figure 6.3. Run power wiring from the disconnect switch to the unit.4. Remove the service access panel to gain access to the unit wiring.Route wires from disconnect through power wiring opening pro-vided and into the unit control box as shown in Figure 6.5. Install the proper size time-delay fuses or circuit breaker, andmake the power supply connections.6. Energize the crankcase heater if equipped to save time by pre-heating the compressor oil while the remaining installation is com-pleted.FIELD CONNECTIONS CONTROL WIRING1. Route low voltage wiring into bottom of control box as shown inFigure 6. Make low voltage wiring connection inside jumper boxper Figures 7-11.2. Replace the corner cover and service access panel that wereremoved in Steps 2 and 4 of the “Field Connections Power Wiring”section.3. All field wiring to be in accordance with national electrical codes(NEC) and/or local-city codes.NOTE: A Start Assist Kit is available and recommended for long line setapplications or in areas of known low voltage problems.4. Mount the thermostat about 5 ft. above the floor, where it will beexposed to normal room air circulation. Do not place it on an out-side wall or where it is exposed to the radiant effect from exposedglass or appliances, drafts from outside doors or supply air grilles.5. Route the 24-volt control wiring (NEC Class 2) from the outdoorunit to the indoor unit and thermostat.NOTE: To eliminate erratic operation, seal the hole in the wall at thethermostat with permagum or equivalent to prevent air drafts affectingthe operation of in the thermostat.DEHUMIDIFICATION CONTROLA dehumidification control accessory 2HU06700124 may be used withvariable speed air handlers or furnaces in high humidity areas. Thiscontrol works with the variable speed indoor unit to provide cooling at areduced air flow, lowering evaporator temperature and increasing latentcapacity. The humidistat in this control opens the humidistat contacts onhumidity rise. To install, refer to Figures 7-11 in this manual and alsorefer to the installation manual packed with the control accessory2HU06700124.Prior to the installation of the dehumidification control, the jumperacross the HUMIDISTAT terminals on the indoor variable speed air han-dler or furnace CFM selection board must be removed.During cooling, if the relative humidity in the space is higher than thedesired set point of the dehumidification control, the variable speedblower motor will operate at lower speed until the dehumidification con-trol is satisfied. A 40-60% relative humidity level is recommended toachieve optimum comfort.If a dehumidification control is installed, it is recommended that a mini-mum air flow of 325 cfm/ton be supplied at all times.For additional connection diagrams for all UPG equipment refer to “LowVoltage System Wiring” document available online at www.upgnet.comin the Product Catalog Section.CFM SELECTION BOARD SETTINGSFor proper system operation the CFM Selection Board jumpers must beset properly.Refer to the Tabular Data Sheet for the recommended air flow settingsfor each size condensing unit.Set the cooling speed per the instructions for the air handler or furnaceby selecting the correct COOL and ADJ taps. Verify the airflow usingthe LED display on the CFM selection board.The HEAT PUMP jumper MUST be removed for proper system opera-tion.The HUMIDISTAT jumper must also be removed if a dehumidistat isinstalled.FIGURE 5: Typical Field WiringCONTROLWIRINGPOWERWIRINGCORNERCOVERSERVICEACCESSPANELFIGURE 6: CFM Selection BoardCFM SELECTION BOARDTAP SELECTIONDCBADCBACOOL HEAT ADJ DELAYREMOVE FORHEAT PUMP HUMIDISTAT