FORM 150.24-NM27
YORK INTERNATIONAL
85
To compute the offset for a given timer closed, use the
formula below:
1. Programmed max. reset
= Reset per sec.
20 seconds
2. (Time Closed-1) Reset per sec. = Reset
Example:
Programmed max reset = 30°; Time Closed = 9 sec.
1. 30°
= 1.5° per sec
.
20 sec.
2. (9 sec. -1 sec.) 1.5° per sec. = 12° = Reset
To determine the new setpoints, add the reset to the
setpoint programmed into memory. In the example above,
if the programmed setpoint = 44°F, the new setpoint af-
ter the 9 second contact closure would be 44°F + 12°F
= 56°F. This new setpoint can be viewed on the display
by pressing the REMOTE RESET TEMP/RANGE key.
To maintain a given offset, the micro must be refreshed
every 30 seconds - 30 minutes with a contact closure of
the required time period. It will not accept a refresh sooner
than 30 seconds after the end of the last PWM signal,
but must be refreshed before a period of 30 minutes ex-
pires from the end of the last PWM signal.
After 30 minutes, if no refresh is provided, the setpoint
will change back to its original value. A refresh is noth-
ing more than a contact closure for the period required
for the desired offset.
NOTE: After an offset signal, the new setpoint may be
viewed on the REMOTE RESET TEMP RANGE
DISPLAY. However, if this display is being viewed
when the reset pulse occurs, the setpoint will
not change on the display. To view the new off-
set, first press any other display key on the key-
pad and then press the REMOTE RESET TEMP
RANGE key. The new setpoint will then appear.
Wiring from these contacts should not exceed 25 ft. and
should be run in grounded conduit that does not carry
any wiring other than control wiring. Additionally, if an
inductive device (relay, contactor) is supplying these con-
tacts, the coil of the device must be suppressed with a
user supplied YORK P/N 031-00808 suppressor.
NOTE: Remote Setpoint Reset will not operate when a
Remote Control Center Option Kit is connected
to the Micro Panel. The Remote Control Center
will always determine the setpoint.
REMOTE UNLOADING
The microprocessor is capable of remote unloading or
pulldown demand limiting in two steps. The first step
shuts down the lag system. The second step unloads
the lead system to its minimum step of capacity which
places the entire system at minimum possible capacity.
To shut down the lag compressor, a dry contact should
be connected between terminals 13 & 16. See Fig. 14
for the location of these terminals. When the contact is
closed, the lag compressor will shut down.
Before the lead system can be unloaded to its minimum
step of capacity, the lag compressor must already be
disabled with a dry contact closure between terminal
13 & 16 as described in the preceding paragraph.
With contacts on Terminals 13 & 16 closed, the lead
system can be unloaded to its minimum step of capac-
ity by closing a dry contact connected between termi-
nals 13 & 17. See Fig. 14 for location of this terminal.
The lead system will remain totally unloaded as long as
the contacts remain closed on both 13 & 16 and 13 &
17. It should be noted that terminals 13 & 17 are nor-
mally used for Remote Setpoint Reset. However, it is
assumed that if the lag system is purposely being shut
down, Remote Setpoint Reset and temperature control
is of no importance. This is generally true since capac-
ity control of the load is lost when a large portion of the
capacity is disabled.
CAUTION: Two cautions should be observed when us-
ing these functions. Observing these cau-
tions will assure that undesirable operation
does not result.
1. Terminals 13 & 17 contact should always be
closed after or simultaneous with those on
13 & 16, when unloading of the lead system
is desired. Otherwise, the microprocessor
may mistake the closed contacts on 13 &
17 as a signal for a setpoint reset.
2. Terminal 13 & 17 contact should always be
opened before or simultaneous with those
on 13 & 16 when loading is desired. Other-
wise, the microprocessor may mistake the
closed contacts on 13 & 17 as a signal for a
setpoint reset.
EVAPORATOR WATER PUMP CONTACT
This control provides a dry contact which can be used
to turn on the evaporator water pump. The contact will
be closed by the micro before the micro brings a com-
pressor on. The micro will not bring a compressor on
until a RUN PERMISSIVE signal is established by a
flow switch contact closure. If no daily schedule is set
(all times = 00.00), the evaporator water pump contact
will transition as soon as a System Switch on the micro-
processor board is placed in the ON position.
If a daily schedule is programmed, the evaporator water
pump contacts will transition when the daily schedule
dictates.
Содержание YCRJ45E00
Страница 29: ...FORM 150 24 NM27 YORK INTERNATIONAL 29 CONTROL CIRCUIT With I O Expansion Board LD02106 ...
Страница 30: ...30 YORK INTERNATIONAL FIG 9 SYSTEM WIRING ...
Страница 31: ...FORM 150 24 NM27 YORK INTERNATIONAL 31 LD02678 ...
Страница 33: ...FORM 150 24 NM27 YORK INTERNATIONAL 33 LD02357 MOTOR TERMINAL BOX WIRING WITH MODEL 31AA MOTOR PROTECTOR ...
Страница 34: ...34 YORK INTERNATIONAL FIG 10 CONNECTION DIAGRAM LD02358 MICROPANEL CONNECTION DIAGRAM WITHOUT EXPANSION BOARD ...
Страница 35: ...FORM 150 24 NM27 YORK INTERNATIONAL 35 LD02679 ...
Страница 36: ...36 YORK INTERNATIONAL MICROPANEL CONNECTION DIAGRAM With I O Expansion Board LD02107 ...
Страница 37: ...FORM 150 24 NM27 YORK INTERNATIONAL 37 LD02108 ...