52
Heat Exchanger Safeties
Electronic freeze protection and water flow
safeties should be field installed or factory
provided. If the leaving water temperature
drops below 38°F or water flow has ceased
the 24VAC control circuit will be broken to
disable the cooling system.
Waterside Economizer
Cooling
and
pre-cooling
waterside
economizer coil is factory installed upstream
of the evaporator coil. An optional field
installed water piping kit includes three fully
modulating water valves (the economizer
valve, economizer bypass valve, and a three-
way head pressure control valve). The water
piping between the waterside economizer
and the water-cooled condenser must be
field
provided.
See
the
waterside
economizer piping figure for recommended
piping.
A p-trap must be installed on the coil drain
outlet, not to exceed 6” from the drain
connection. See the previous section on
condensate drain piping for additional p-trap
and drain information.
Figure 23 – Waterside Economizer Piping
The waterside economizer circuit can
operate
in
three
modes:
waterside
economizer only, waterside economizer with
mechanical cooling, and mechanical cooling
only.
During waterside economizer only mode of
operation, condenser water flows through
the
waterside
economizer
coil
with
modulating valves maintaining supply air
temperature setpoint. The condenser water
completely
bypasses
the
water-cooled
condenser.
During
waterside
economizer
with
mechanical cooling mode of operation,
100% of the condenser water flows through
the waterside economizer coil. The
condenser water then passes through the
water-cooled condenser and the three-way
valve modulates to maintain head pressure.
Do
not
exceed
recommended
condenser fluid flow rates. Serious
damage to or erosion of the heat
exchanger tubes could occur.
DRAIN PAN CONNECTION
With a waterside economizer coil a
separate
drain
connection
is
included. Failure to use this separate
drain connection may result in water
backup and overflow of drain pan.
CAUTION
CAUTION
F
IELD
P
R
O
V
ID
ED
Summary of Contents for M2 Series
Page 2: ......
Page 5: ...5 Split System Piping Diagrams 98 M2 Series Startup Form 115 Maintenance Log 121 ...
Page 35: ...35 Table 1 Electric and Gas Heating Capacities ...
Page 38: ...38 Figure 5 M2 Series Unit Four Point Lifting ...
Page 39: ...39 Figure 6 M2 Series Unit Eight Point Lifting ...
Page 58: ...58 Figure 32 Supply Fan Banding ...
Page 95: ...95 Figure 52 Filter Layout Viewed from the Upstream Side of the Cooling Coil ...
Page 98: ...98 Split System Piping Diagrams Figure 53 A C Split System Piping Suction Down ...
Page 99: ...99 Figure 54 A C Split System Piping Suction Up ...
Page 100: ...100 Figure 55 A C with LAC Split System Piping Suction Up ...
Page 101: ...101 Figure 56 A C with Modulating Hot Gas Reheat Split System Piping Suction Down ...
Page 102: ...102 Figure 57 A C with Modulating Hot Gas Reheat Split System Piping Suction Up ...
Page 103: ...103 Figure 58 A C with Hot Gas Bypass Split System Piping Suction Down ...
Page 104: ...104 Figure 59 A C with Hot Gas Bypass Split System Piping Suction Up ...
Page 107: ...107 Figure 62 Heat Pump Split System Piping Suction Down ...
Page 108: ...108 Figure 63 Heat Pump Split System Piping Suction Up ...
Page 109: ...109 Figure 64 Heat Pump with Modulating Hot Gas Reheat Split System Piping Suction Down ...
Page 110: ...110 Figure 65 Heat Pump with Modulating Hot Gas Reheat Split System Piping Suction Up ...
Page 111: ...111 Figure 66 Heat Pump with Hot Gas Bypass Split System Piping Suction Down ...
Page 112: ...112 Figure 67 Heat Pump with Hot Gas Bypass Split System Piping Suction Up ...