ABB ACS880-87LC-4000A/4021A-7, Руководство по оборудованию

Страница: 131 / 144

Cooling and heating 131
Planning the cooling system

Connection to a customer cooling unit
General requirements
Equip the system with an expansion tank to damp pressure rise due to volume changes
when the temperature varies. Keep the pressure within the limits specified in
Specifications below. Install a pressure regulator to ensure that the maximum permissible
operating pressure is not exceeded.
Install a bleeding valve at the highest point of the cooling circuit. Bleeding valve is not
included in the ABB converter delivery as standard. It can be ordered as an option
(+G422).
The materials used in the cooling system are listed in Specifications on page 136 .
Coolant temperature control
The temperature of the coolant in the internal cooling circuit must be kept within the limits
specified in
Specifications on page 136 . Note that the minimum temperature depends on
ambient temperature and relative humidity.
The following diagram shows an example of coolant temperature control using the three-
way valve in the external cooling circuit. Part of the infeed coolant flow is directed into the
return pipe through a three-way valve without letting it circulate in the internal cooling
circuit if the coolant in the internal circuit is too cold.
Infeed
TC
Return
External circuit Internal circuit