Trane BAYRLAY004A - Economizer Checkout Procedure; Motor Operation Checkout; Single Enthalpy Checkout

Page 7
INSTALLER’S GUIDE
Checkout
Figure 7. SINGLE ENTHALPY CHANGEOVER SET POINT
Single enthalpy: The enthalpy
changeover set point is set to return the
outdoor air damper to minimum posi-
tion when the enthalpy rises above its
set point. The enthalpy set point scale
markings, located on W7459, are
A,B,C,D; see table for the correspond-
ing control point. The factory-installed
R4 WHITE 620-ohm jumper must be in
place across terminals + and SR.
Operate the motor through its complete open-close
stroke. If necessary, release one of the previously
tightened linkage connections to prevent damage.
Check for proper operation, making sure that the
linkage does not bind and that the motor travels
smoothly throughout its fully open and closed posi-
tion. Table 1 describes how to drive motors full open
and closed (power connected). If there is excess
length of linkage rod, cut it to size. Make necessary
minor adjustments until desired operation is ob-
tained, and tighten all nuts and set screws. This
motor checkout ensures that:
1. The motor operates the load.
2. The motor responds properly to the controller.
3. There is no binding of the linkage or motor
stalling at any point of travel.
If motor does not operate properly, check for
proper voltage or mechanical binding in linkage or
damper.
If questions arise regarding this product, contact
your distributor or representative.
CONTROL
CURVE
A
B
C
D
CONTROL POINT
APPROX. F ( C)
AT 50% RH
73 (23)
70 (21)
67 (19)
63 (17)
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
44 46
90
100
80
70
60
50
40
30
20
10
ENTHALPY—BTU PER POUND DRY AIR
85
(29)
90
(32)
95
(35)
100
(38)
105
(41)
110
(43)
35
(2)
35
(2)
40
(4)
40
(4)
105
(41)
110
(43)
45
(7)
45
(7)
50
(10)
50
(10)
55
(13)
55
(13)
60
(16)
60
(16)
65
(18)
65
(18)
70
(21)
70
(21)
75
(24)
75
(24)
80
(27)
80
(27)
85
(29)
90
(32)
95
(35)
100
(38)
APPROXIMATE DRY BULB TEMPERATURE— F ( C)
A
A
B
B
C
C
D
D
M11681
RELATIVE HUMIDITY (%)
1
1
HIGH LIMIT CURVE FOR W7459D.
MODEL DRIVE MOTOR OPEN DRIVE MOTOR CLOSED SPRING RETURN
M7415 Power to TR and TR1, jumper T and T1.
Disconnect jumper at T or T1 and
disconnect P or P1,if connected.
Disconnect power at TR and TR1.
Table 1. Motor Operation Checkout