JOHNSON CONTROLS
78
FORM 155.32-ICOM1.EN.GB
ISSUE DATE: 10/13/2017
SECTION 5 - COMMISSIONING
PRECAUTIONS FOR THE USE OF WATER
Staining and corrosion of the tubes in the evapora-
tor, absorber, and condenser depends on the quality of
the water used as chilled/hot water and cooling water.
Water quality must be checked periodically to pre-
vent problems. If water quality is not controlled and
maintained properly, premature tube failure can result.
Causes of bad quality water include:
•
Polluted seawater
•
Polluted underground water
•
Cooling tower located near a chimney or in dirty
air
Be sure to analyze the chilled/hot water
and the cooling water within one month
after commissioning. See Table 23 on
Install strainers of 10 mesh and above to the chilled/hot
water and cooling water inlets.
Shut off valves will be installed at the customer site
in the chilled/hot water, and cooling water inlets and
outlets. Be sure the valves are completely open when
suppling water. If not, the water flow can become tur-
bulent (at the shut off valves) and damage the water
chamber case and tubes. When you need to reduce the
quantity of the chilled/hot water, and cooling water
temporarily, use the valves to make adjustments.
When the flow rate change of the chilled/hot water is
controlled (if the flow rate change function is installed),
the load change speed is limited.
•
The load change condition to limit the chilled/hot
water temperature at the outlet is ±0.5°C : 1.5%/
minimum maximum.
•
The critical load change condition to prevent an
overcooling trip of the chiller-heater is 5%/mini-
mum maximum.
CHILLED/HOT WATER OUTLET
TEMPERATURE CONTROLLER
The chilled/hot water outlet temperature controller
(23A) is located on the sequencer and controls the
chilled/hot water outlet temperature.
LIQUID LEVEL GAUGES
Liquid level gauges are used to check the conditions of
the chiller-heater components.
TABLE 29 -
LIQUID LEVEL GAUGES (SIGHT
GLASS)
LIQUID LEVEL
GAUGE NAME
SYMBOL
FUNCTION
Refrigerant overflow
monitoring level gauge
G101
Checks refrigerant
overflow level
Refrigerant tank level
gauge
G102
Checks lower limit of
refrigerant tank level
Absorber level gauge
G103
Checks lower limit of
absorber
HT-GEN level gauge
G104
Checks condition
of solution in high-
temperature generator
LT-GEN level gauge
G105
Checks condition
of solution in low-
temperature generator
