APC ACPDX21-86 User Manual

Humidifier
The humidifier utilizes a pure 
steam generator specifically 
designed for precision 
environmental close control. The 
pure steam eliminates 
contaminating mineral deposits, 
potentially harmful bacteria, 
white dust, and excessive 
humidity. The humidifier requires 
little scheduled maintenance.  The 
humidifier is proportionally 
controlled to meet the 
humidification demands of the 
conditioned space.  Humidifier 
canisters are replaceable.

Electric reheat elements are low 
watt density, wired for 3-phase 
and loaded equally on all three 
phases, SCR controlled, and 
electrically and thermally 
protected by both automatic and 
manual reset thermal cut outs. 
Reheat coils are stainless steel, 
tubular fin construction.

Spot Water Detector
The solid-state spot water 
detector is available for both 50 
and 60 Hz cooling units. The spot 
water detector activates an 
audible alarm on the controller 
when moisture is detected. 

Smoke Detector
The factory-installed smoke 
detector is designed to sense 
smoke in the return air stream. 
Upon detection of smoke, an 
audible and visual alarm on the 
microprocessor controller will be 
activated and the unit will be shut 
down immediately.

Hot Gas Bypass Valve
The hot gas bypass valve 
(HGBV) adjusts the flow of 
compressor discharge gas to the 
evaporator coil at low load 
conditions to protect the coil from 
freezing and the compressor from 
excessive cycling. 60 Hz cooling 
units use a mechanical HGBV. 
50 Hz cooling units use an 
electronically controlled HGBV. 
On 50 Hz cooling units, the 
HGBV option requires the analog 
extension board EAIO.

Cable Leak Detector (60 Hz 
only)
The optional 6 m (20 ft) leak 
detection sensing cable (APC part 
number ACAC75105) is available 
for 60 Hz cooling units only. The 
cable leak detector is placed on 
the floor or subfloor around all 
possible leak sources. If water or 
other conductive liquids contact 
the cable anywhere along its 
length, the master controller 
visually and audibly announces 
the leak.

Floorstand
The floorstand raises the unit 
above the subfloor to match the 
height of the raised floor. Heights 
are available from 254 mm  (10 
in) to 610 mm  (24 in) in 76.2 mm  
(3 in) increments and are 
adjustable +/– 38.1 mm  (1.5 in). 
Adjustment is provided by 
threaded pedestals. Vibration- 
absorbing pads are included. The 
floorstand, pedestal, and pads 
ship loose. In areas where 
earthquakes are a concern, 
seismic floorstands are available 
in 305 mm (12 in), 457 mm (18 
in), and 610 mm (24 in) heights.

Plenums
Discharge plenums are available 
on upflow configurations. This 
application is recommended in 
rooms where raised floors are not 
available for air distribution.  
Discharge air should be ducted 
down cold aisles. 

Base Plenum
Insulated base plenums are 
available for downflow cooling 
units where raised floors are not 
available for air distribution. Four 
front-discharge configurations are 
available equipped with dampers, 
grilles, flexible ductwork or open. 
All configurations are 450 mm 
(17.7 in) high and sit beneath the 
InRoom cooling unit.

Water Regulating Valves
Water and fluid cooled systems 
utilize two- or three-way valves to 
regulate the amount of water or 
glycol supplied to the condenser 
in response to refrigerant 
discharge pressure.  The standard 
valve pressure rating is 28 kPa 
(400 psi).

Extreme Low Temperature 
Kit (Direct Expansion units 
only)
Extreme Low Temperature Kits  
for air cooled condensers are 
available for operation below 
–34.4°C (–30°F).  The optional 
kit consists of pressure control 
valves and receivers for the liquid 
return side of the refrigerant 
piping.