Specifications

530.25-N1
2. Install two 1/4” O.D. tubes, one between the filters and
the air entering side of the evaporator coil and one be-
tween the supply air blower(s) and the air leaving side
of the evaporator coil.
5/1 6“ DIA
I
1
5116“ DIA.
/
B
o \
= IJNIT
DRAIN
RIGHT END
VIEW
k
30”
-t- 33”
FIG. 16 – HOLE LOCATIONS FOR SUPPLYAIR
CFM CHECK
—
—
—
—
NOTE: To@ a properstatic pressurereading,the
sensing
3.
4,
. .
tubes should (A) be inserted through the rearor -
contitwsate drainside of the unit (B) be lttcnted
approxittwtel>’6 inches awa.t’jrorn the coil surjace
and as close to the center c)]”[he coil heigh[as pos-
sible (C) e.rtend into the utut appro.~itnate(vt12
inches.
Make sure that the accesspanels for both the supply air
blower motor and the filters are ptirtially secured. These
panels do not have to be secured where the 1/4 inch tubes
enter the uruts because the blow’er and f“iltercrrmpart men[s
operate at a negatwe pressure.
Make sure that the tube openings are perpendicular to the
air flow so that veloclt y pressure WI]] not affect the static
pressure readings.
C4
UTIOiV [frhis method is used, the h<~kymust he sealed
wifh dot plugs (P/,J’029-13880) or equit’alent
t[]prcrtwt mois?urcjkotn leaking into thc~[[nit.
+0 80 90
100
I io
120
130
PERCENT NOMINAL CFM
I
% OF NOM INA L CFM
MODEL 80 90
100
110
120
C F .M.
DSC300
8000
9000
10000 11000 t 2000
DSC360 9600
10800
12000
13200
14400
DSC480
‘1 2800 14400 16000 17600
19200-
FIG. 17 – PRESSUREDROP ACROSS A DRY
EVAPORATOR COIL VS SUPPLY AIR CFM
5. Using an ~nclined manometer, determine the pressure drop
acrossa dry evaporator cod, Since the moisture on tin evap-
orator coi] may vary greatly, measuring the pressure drop
acrossa wet coI] under field condIt Ions WOUICIbe Inticcu-
rate.
IJ10T15’Discc)tmectthe <ontpre,sw~t-sbi~fi)retuking ant tesl
measuwtncnts to assut-da tlrl’el’apc]rutorcoi[.
6. Knt)wlng the pressure drop acrossa dry coil, the actual
(’FM thr[)ug}~the unit cun be determined iron] the crrrvc
in Figure 17.
If the CFM ISabove or below tlte specified value, t}lc supply
alr motor pu]ley may have to be readjusted.
After (me hour
of
operat [on, check ail belt\ and pulleys for t@lt nes~and
aIIgntnent.
MASTER PRINTED CIRCUIT BOARD & PLUG-IN
Two lumper p]LIgs.one led and one w]ute, ~1e k)cated al tite
RELAY ASSEMBLY
top of the board. When they are [emo~ed ~nd replaced wltb
All of the control”reloys that are required for unit operation
are mounted on the printed clrcult bool d Fgure 9, 10 or I 1
shows this assembly W}IICII IS located In the ma]n cent r[]l pan
el. All of the relays are of the plug-in valiet}, II(J wil ]ng COIE
nections have to be removed to replace a relay. S]nce the re-
lays are transparent, the mechanical contact switclung can be
observed f’or easier elect rlcal troubleshoot lng.
The low voltage field wiring ISto be connected along the top
of the printed circuit board at the eyelet connections, Each
termmal ISmarked both numerlca]ly and with letters corres-
ponding to the rooni thermostat for easier installation
the connectors of the service analyzer, the analy/er WIII l)ver-
Iide the rm~m thermostat.
All s)stem func[l{)ns suCII .Is IICUI-
ing, coo]ing, econonllzer, and nlght set-back can be slrnul~ted.
Mall[lnct I(,II mdIctit[)I llgl)t~ irIe provided to de[ermme WIIICII
system 110sm~l[ unctioned.
C-AUTIO,}’, Whenremo~mg the cotltlector.ro~”thescrtw
attal~)zer,the two juniper plugs ((me red atld (ml’
)tyhite)must be reinstalled into rheirproper w)c-
kets b~;fiw the s~~[etncanjunc[IcNI.
The procedule for troubleslumt mg o unit with a service ana-
ly/er ctmnectecl to lts pr~nteclCIIcult blurcl ISoutlined below.
18
CES