Ramp Loading Control
The ramp loading cont rol slows down the rat e at which the compr essor loads up. This c ontrol
can prevent the compre s s or fro m loading up during the s ho rt period of time when t he m ac h ine
is started, and the chille d water loop has to be broug ht down to normal design conditions. This
helps reduce electrical demand charges by s lowly bringing the chilled water to contro l point.
However, the total pow er dr aw during this period rema ins almost unchange d.
There are 2 methods of ramp lo ading with the PIC. Ramp lo ading can be based on chi lle d
water temperature or on motor load.
1. Temperature ramp load ing limits the rate at which either leaving chill ed water or entering
chilled water temperature decreases by an operator-configured rate. The lowest
temperature ramp tab le will be used the first time the machine is started (at
commissioning). T he lo west temperature ra m p r at e will also be used if mach ine power has
been off for 3 hours or more ( ev e n if the motor ramp load is s ele cted).
2. Motor load ramp loading limits the rate at which the compressor motor current or
compressor motor load increases by an operator-configured rate.
The

TEMP

(

Temperature

)

PULLDOWN, LOAD PULL DO WN

, and

SELECT RAMP TYPE

may be viewed/modifie d on the LID Equipment Conf iguration table, Co nfig table (see Table 2).
Motor load is the default type.