York 251934-YTG-J-0910 manual For 5-hp motor applications

251934-YTG-J-0910

pressure in the supply duct. A pressure transducer and VAV control board are mounted inside the control box. The drive comes completely wired and pre-programmed from the factory.

An optional, factory-installed manual bypass switch available with factory-installed VFD can be found in the Blower Motor Access compartment. The switch can be used to either route power to the VFD for modulating control of the blower motor, to bypass the drive and operate the motor at full speed, or to power the drive (and not the motor) for diagnostic purposes.

Due to space limitations, VAV is not available with any of the factory-installed BAS options described below, but is available with ‘BAS-ready’ models. Terminal blocks are provided in the control box for field wiring of the customer- installed BAS.

A ‘VFD-ready’ option provides the provisions for a customer-installed drive. The unit comes with a mounting bracket installed in the Blower Access compartment which may accommodate other vendor’s drives depending on their size. In order to utilize the unit’s mounting bracket, the maximum recommended drive dimensions are as follows:

For 5-hp motor applications	13” H x 6” W x 7” D
For 7.5 thru 15-hp motor applications	13” H x 8” W x 8” D

If the drive will not fit in the allotted space, then it will have to be mounted elsewhere; either within the building on a perpendicular wall which is not subjected to excessive temperature, vibration, humidity, dust, corrosive gas, explosive gas, etc., or within an appropriate enclosure rated for outside installation to safeguard against moisture, dust and excessive heat.

A terminal block located in the control box is provided for field connection of the VFD controls.

•Hot Gas Bypass - To allow for low cooling load operation, a direct-acting pressure-modulating bypass control valve installed on the system #1 discharge line is used to divert high temperature, high pressure refrigerant around the TXV in order to maintain a desired minimum evaporator pressure. HGBP is standard on all units with VAV and optional with CV units.

•Filter Options - Standard units are shipped with 2" throw- away filters installed. 2" pleated and 4" pleated filters are offered as a factory installed option.

•Convenience Outlet - This 110 volt outlet can be "powered" by the unit with a stepdown transformer or you may order the unit with a "non-powered" convenience outlet that can be wired in the field.

•Disconnect Switch - For gas heat units and cooling units with electric heat, a HACR breaker sized to the unit is provided. For cooling only units, a switch sized to the largest electric heat available for the particular unit is provided. Factory installed option only.

•Double Wall Construction - Optional double wall construction is available to provide smooth inner surfaces for easy and effective cleaning to reduce risk of dirt and bacterial accumulation. Fiberglass insulation is sandwiched

between heavy gauge steel sheets to form a durable, rigid casing to withstand higher working pressures and impact forces. The heavy-duty construction provides excellent acoustic and thermal insulation and eliminates erosion of insulation material and contamination of the air stream.

•York Commercial Comfort System (YCCS) - Provides rooftop system integration for YCCS single zone, change- over bypass and VAV systems.

•Smoke Detectors - (supply air & return air) The smoke detectors stop operation of the unit by interrupting power to the control board if smoke is detected within the air compartment.

Factory installed smoke detectors in the return air, may be subjected to freezing temperatures during “off” times due to out side air infiltration. these smoke detectors have an operational limit of 32°F to 131°F. smoke detectors installed in areas that could be out side those limitations will have to be moved to prevent having false alarms.

•Coil Guard - Customers can purchase a coil guard kit to protect the condenser coil from damage. This is not a hail guard kit.

•Stainless Steel Heat Exchanger - For applications in corrosive environments, this option provides a full stainless steel heat exchanger assembly.

•Stainless Steel Drain Pan - An optional rustproof stainless steel drain pan is available to provide years of trouble-free operation in corrosive environments.

•Phase Monitors - Designed to prevent unit damage. The phase monitor will shut the unit down in an out-of phase condition.

•High Static Drive - May include a belt, blower pulley, motor pulley or a motor change to enhance blower performance.

•Low Static Drive - May include a belt, blower pulley, motor pulley or a motor change when standard airflow is not required. (ZJ/ZR/ZF300 only).

•Dirty Filter Switch - This kit includes a differential pressure switch that energizes the fault light on the unit thermostat, indicating that there is an abnormally high pressure drop across the filters. Factory installed option or field installed accessory.

•Hinged Filter Door/"Tool Free" Blower And Access Panels (Not Hinged) - This option allows for easy access and maintenance.

NOTE: Knobs are shipped separately within the unit to prevent shipping damage. These must be field installed for tool free operation.

•Hinged/"Tool Free" Blower, Blower Motor, Filter And Electric Access Panels - This option allows for complete hinged and tool free access to the unit’s blower, blower motor, filters and electrical panel sections.

Johnson Controls Unitary Products 7