Schneider Electric 58 TRX manual Thermal Management, 225

Class 8998 Motor Control Centers

Sample Specifications

shall be connected directly to the main horizontal bus with appropriately size cable or riser bus.

f.All AC drive controller units shall be enclosed in a structure which contains a 12" (305 mm) high horizontal wireway at the top of each section, and a 6" (152 mm) high horizontal wireway at the bottom of each section. These wireways should be unobstructed the full length of the motor control center to allow room for power and control cable to connect between units in different sections.

g.A full-depth vertical wireway shall be provided within motor control center sections containing AC drive controller units up to 50 hp variable torque. The vertical wireway shall connect both the top and bottom horizontal wireways, and shall be isolated from the AC drive controller unit interiors by a full height barrier. The vertical wireway shall be at least 4" (102 mm) wide with a separate hinged door. There should be a minimum of 4,000 cubic inches (65,548 cubic millimeters) of cabling space available. Access to the wireways shall not require opening control unit doors. AC drive controller units that require a full section are not required to have vertical wireways.

h.All AC drive controller unit interior mounting panels shall be white for better visibility inside.

i.The motor control center structure shall include unit mounting shelves with hanger brackets to support AC drive controller units up to 50 hp variable torque during installation and removal. A twin handle camming lever shall be located at the top of AC drive controller units up to 50 hp variable torque to rack the unit in and out.

j.A cast metal handle operator shall be provided on each AC drive controller unit disconnect. With the AC drive controller unit connected to the motor control center bus and the AC drive controller unit door closed, the handle mechanism shall allow complete on/off control of the unit disconnect, with clear indication of the disconnect’s status. All circuit breaker operators shall include a separate tripped position to clearly indicate a circuit breaker trip condition. It shall be possible to reset a tripped circuit breaker without opening the control unit door.

1.A mechanical interlock shall prevent an operator from opening the AC drive controller unit door when the disconnect is in the on position. Another mechanical interlock shall prevent an operator from placing the disconnect in the on position while the AC drive controller unit door is open. It shall be possible for authorized personnel to defeat these interlocks.

2.A non-defeatable interlock shall be provided between the handle operator and the structure to prevent installing or removing a plug-on AC drive controller unit unless the disconnect is in the off position.

k.Provisions shall be provided for locking all disconnects in the off position with up to three padlocks.

l.All plug-on AC drive controller units shall have a grounded stab-on connector which engages the vertical ground bus prior to, and releases after, the power bus stab-on connectors.

m.Handle mechanisms shall be located on the left side to encourage operators to stand to the left of the unit being switched.

n.Unit construction shall combine with the vertical wireway isolation barrier to provide a fully compartmentalized design.

o.All AC drive controller units shall be provided with unit control terminal blocks for use in terminating field wiring. Terminal blocks shall be pull-apart type, 250 Vac, and rated for 10 A. All current-carrying parts shall be tin-plated. Terminals shall be accessible from inside the unit when the unit door is opened. The stationary portion of the terminal block shall be used for factory connections and will remain attached to the unit when the portion used for field connection is removed. The terminals used for field connections shall be accessible so they can be wired without removing the unit or any of its components.

2.04 Thermal Management

a.The AC drive controller unit shall incorporate a self-contained air-based cooling system. Any air exhaust vents shall be louvered to help direct air flow away from personnel operating the AC drive controller unit. Any fans, ductwork, or filters shall be easily accessible for maintenance.

b.The AC drive controller unit cooling system shall be sized to cool the drive regardless of mounting location within the motor control center. The AC drive controller unit shall not be restricted to a specific location in the motor control center.

09/2003

225

© 2000–2003 Schneider Electric All Rights Reserved