Maintenance; Sizing - Devair DRD 200 Instruction Manual

Dryer Driven Mode- the contacts will be energized
and de-energized in parallel with the refrigeration
compressor of the dryer. Therefore, if the refrigera-
tioncompressor is on, the contacts are energized; if
the refrigeration compressor is off (manually or by a
system fault condition), the contacts will be de-
energized.
NOTE: It is the responsibility of the end-user to properly
design the system control circuitry when using the
auxiliary contact feature.
To select Schedule Driven or Dryer Driven modes:
1. De-energize unit and disconnect the power
supply to the dryer.
2. Remove the cabinet panels as necessary to
provide access to the Monitor panel.
3. On the rear of the circuit board, locate the
jumper pins labeled JA and JB.
4. Move the jumper to the appropriate setting:
Schedule Driven: jumper position JA
Dryer Driven: jumper postion JB
5. Wire the auxiliary device into the terminals
1 (Normally Open), 2 (Common) and/or 3
(Normally Closed) on the terminal block TB2.
See wiring diagram for details.
6. Reinstall the cabinet panels.
7. Energize the unit.

3.0 MAINTENANCE

3.1 Condenser coil—Clean off accumulated dust
and dirt monthly.
3.2 Moisture separator—Replace filter element
when pressure drop across dryer is excessive
or annually.
3.3 Check separator daily to be sure automatic drain
is discharging.
3.4 Blow down separator weekly by pushing test
button on control panel.
3.4 Rebuild drain mechanism annually.
To facilitate service, maintenance kits are available.
Threads
Element o-ring
Bowl o-ring
Threads
Separator Element
For Sales & Service Call: 705-722-5747 Ext.1

SIZING

Determining dryer capacity at actual operating conditions
To determine the maximum inlet flow capacity of a dryer
at various operating conditions, multiply the rated capacity
from Table 1 by the multipliers shown in Table 2.
Example: How many scfm can an air-cooled model 400
handle when compressed air to be dried is at 200 psig and
100°F; ambient air temperature is 80°F; and a 40°F dew
point temperature is desired?
Answer: 400 x 1.22 x 1.12 x 1.1 = 601 scfm.
TABLE 1
Rated capacity (scfm) and pressure drop @ 100 psig inlet
pressure, 100°F inlet temperature, and 100°F ambient
temperature
MODEL
Rated capacity of 60 Hz
air-cooled models (scfm) 50 Hz
TABLE 2
Air capacity correction factors (Multipliers)
INLET COMPRESSED AIR CONDITIONS
PRESSURES 80°F
psig kgf/cm 2 27°C
50 3.5 1.35
80 5.6 1.50
100 7.0 1.55
125 8.8 1.63
150 10.5 1.70
175 12.3 1.75
200 14.0 1.80
COOLING MEDIUM*
AMBIENT
TEMPERATURE MULTIPLIER
°F °C
80 27 1.12
90 32 1.06
100 38 1.00
110 43 0.94
*Air-cooled models; water-cooled models use 1.15 multiplier if cooling
water is below 35 ° C, 95 ° F.
200 250 300 400
200 250 300 400
170 210 250 340
INLETINLET TEMPERATURES
90°F 100°F 110°F
32°C 38°C 43°C
1.05 0.84 0.69
1.17 0.95 0.79
1.23 1.00 0.82
1.31 1.07 0.91
1.37 1.13 0.95
1.42 1.18 0.99
1.47 1.22 1.03
OUTLET DEWPOINT
DEWPOINT
TEMPERATURE MULTIPLIER
°F °C
38 3
40 4
45 7
50 10
500 750
500 750
420 630
120°F
49°C
0.56
0.66
0.70
0.74
0.80
0.84
0.89
1.0
1.1
1.2
1.3
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