Initial Control Checkout; And Adjustment; Preparation; Energize Control Circuit - Carrier 16JT Series Start Up & Operation Manual

To charge refrigerant into the evaporator, fill clean solu-
tion containers with the distilled or deionized water. Charge
the water through the refrigerant pump service valve, fol-
lowing the appropriate steps in Charging Solution section.
Charge in at least the amount listed in Table 3 under Ini-
tial Refrigerant amount. This charge must be adjusted after
start-up to achieve optimal Cycle-Guard™ control condi-
tions to limit the maximum solution concentration (which
prevents solution crystallization). However, any extra re-
frigerant should be limited because the normal refrigerant
pump discharge pressure is below atmospheric pressure and
a vacuum bottle is required to remove refrigerant (see Final
Refrigerant Charge Adjustment section, page 25).
Table 3 — Nominal Machine Charges*
LiBr SOLUTION
UNIT
16JT
Gal
810,812,814 137
816,818,821 200 1225
824 246 1505
828 257 1575
832 309 1890
836 314 1925
841 366 2240
847 400 2450
854 440 2695
857 463 2835
865 514 3150
873 560 3430
880 623 3815
080 754 4620
090 846 5180
100 903 5530
110 1017 6230
120 1097 6720
135 1263 7740
150 1377 8435
080L 823 5040
090L 922 5650
100L 1006 6160
110L 1114 6825
120L 1200 7350
135L 1380 8450
150L 1504 9210
*Based on 55% concentration of solution, 44 F (7 C) leaving chilled water,
85 F (29 C) entering condensing water.

INITIAL CONTROL CHECKOUT

AND ADJUSTMENT

The checkout procedures in this section are for semi-
automatic control systems. The purpose of the checkout is to
ensure that control circuits have not been affected by ship-
ping or installation damage or altered in the process of mak-
ing field wiring connections.
NOTE: Some thermoswitch adjustments are scaled in Cel-
sius, hence that is the temperature stated first in some of the
instructions in this manual.
Follow the checkout sequence in detail. Machine must
be charged with solution and refrigerant before starting
checkout. Chilled water and condensing water circuits
must be filled and operative, but the manual steam or
hot water valve must remain closed.
Do not rotate hermetic pumps until machine is charged
with lithium bromide-water solution and refrigerant.

Preparation

1. Open the control panel and place the main circuit breaker
in OFF position (Fig. 13) to deenergize the control circuit
and pump motor.
2. Disconnect leads for solution pump motor and refriger-
ant pump motor at secondary starter terminals. Wrap the
ends of the disconnected wires with electrical tape and
mark for proper identification at reinstallation.
INITIAL REFRIGERANT
Kg Gal Kg
840 87 330
106 400
92 350
92 350
114 430
114 430
137 520
137 520
165 625
165 625
203 770
232 880
285 1080
177 670
201 760
215 815
202 765
206 780
238 900
271 1025
197 745
211 800
225 850
219 830
238 900
277 1050
304 1150
3. If starters for condensing water pump and chilled water
pump are operated by manual start-stop, temporarily place
an insulated jumper between terminals P1 and P2 to over-
ride the external interlock. Remove fuses from starters
for the condensing water pump motor and chilled water
pump motor. (Starters for these motors are field supplied
on external voltage lines and are not located in control
panel.)
If condensing and chilled water flow switches are used,
manually block the switches closed.
IMPORTANT: Do not open manual steam or hot
water valves.

Energize Control Circuit

1. Place the main circuit breaker in the ON position to en-
ergize control circuit. (Stop light turns red.)
2. Depress the Stop button to clear any safety fault condi-
tions and to prepare the control circuit for starting.
3. Place the control panel settings in the following
positions:
SETTINGS
Capacity Control
Cycle Guard Switch
Local/Remote Switch
4. Depress the Start button momentarily to start the ma-
chine. The Run light turns green and the start cycle be-
gins.With normal operation, the solution pump starts im-
mediately and the refrigerant pump starts after about
5 minutes.
Check Solution and Refrigerant Pump
Starters
1. Make sure the solution and refrigerant pump starters are
energized.
2. Depress the Stop button momentarily (Run light de-
energizes). Both starters remain energized for approxi-
mately 15 minutes during dilution cycle (Dilution light
energizes).

Check Pump Starter Overloads

1. Depress the Start button, and wait for the pumps to start.
2. Push the trip bar on the side of the refrigerant pump starter
overload. All pump starters deenergize, the alarm buzzer
sounds, and the fault light identifies the fault category.
3. Depress the Stop button (to silence the alarm) and the
starter reset bar.
4. Repeat Steps 1 - 3 with other control panel starters. Refer
to the wiring diagrams for the set point of each starter.
5. Starters for auxiliary equipment must be similarily checked,
according to the manufacturers' instructions.

Check Low-Temperature Cutout

1. Turn the differential adjustment screw until differential
set point is at 4 C (7.2 F).
2. Place control sensing bulb in a water bath maintained at
9° F (5° C) below design leaving chilled water tempera-
ture (but not below 36 F [2 C]). This is the correct low-
temperature cutout setting.
3. Depress the Start button.
Slowly turn cutout adjustment knob clockwise until con-
tacts open. Chilled water, condensing water, solution and
refrigerant pump starters, and Run light should de-
energize, the alarm buzzer should sound, and the fault
light should identify the fault category.
22
POSITION
AUTO.
AUTO.
LOCAL