21
Table 6 — 50RWS036-360 Operating Limits
Unit Start-Up
1. Turn off all power to unit.
2. Adjust all valves to full open position.
3. Restore power to unit.
4. Operate each unit in the cooling cycle. See Table 6 for
unit entering water temperatures.
5. Operate each heat pump in the heating cycle immediately
after checking cooling cycle operation.
NOTE: A time delay will prevent the compressor from
re-starting for approximately five (5) minutes. The time
delay function can be overridden on the Complete C con-
trol board.
6. If unit fails to operate, perform the following system
checks:
a. Check the voltage and current. Be sure they com-
ply with electrical data on unit nameplate.
b. Check for loose terminal screws where wire con-
nections have been made on both the line and low-
voltage terminal boards.
c. Check the supply and return piping. Be sure they
are properly connected to the inlet and outlet con-
nections on the unit.
d. If the checks described above fail to reveal the
problem and the unit still will not operate, contact
a trained service technician to ensure proper
diagnosis.
Scroll Compressor Rotation —
It is important to be
certain compressor is rotating in the proper direction. To
determine whether or not compressor is rotating in the proper
direction:
1. Connect service gages to suction and discharge pressure
fittings.
2. Energize the compressor.
3. The suction pressure should drop and the discharge
pressure should rise, as is normal on any start-up.
If the suction pressure does not drop and the discharge
pressure does not rise to normal levels:
1. Turn off power to the unit. Install disconnect tag.
2. Reverse any two of the unit power leads.
3. Reapply power to the unit and verify pressures are cor-
rect. The suction and discharge pressure levels should
now move to their normal start-up levels.
After a few minutes of reverse operation, the scroll com-
pressor internal overload protection will open, thus activating
the unit lockout. This requires a manual reset. To reset, turn the
thermostat on and then off.
NOTE: There is a 5-minute time delay before the compressor
will start.
Flow Regulation —
Flow regulation can be accom-
plished by two methods. Most water control valves have a flow
adjustment built into the valve. By measuring the pressure drop
through the unit heat exchanger, the flow rate can be deter-
mined. Adjust the water control valve until the flow of 1.5 to
2 gpm is achieved. Since the pressure constantly varies, two
pressure gages may be needed in some applications. See
Table 7 for heat exchanger pressure drops.
An alternative method is to install a flow control device.
These devices are typically an orifice of plastic material de-
signed to allow a specified flow rate that are mounted on the
outlet of the water control valve. Occasionally these valves
produce a velocity noise that can be reduced by applying some
back pressure. To accomplish this, slightly close the leaving
isolation valve of the well water setup.
Table 7 — Heat Exchanger Pressure Drop
Source/Outdoor Coax
Load/Indoor Coax
Cleaning and Flushing —
Cleaning and flushing of
the piping system is the single most important step to ensure
proper start-up and continued efficient operation of the system.
Follow the instructions below to properly clean and flush
the system:
1. Verify electrical power to the unit is disconnected and
lockout tag installed.
2. Install the system with the supply hose connected directly
to the return riser valve. Use a single length of flexible
hose.
WATER LIMITS
COOLING
(F)
HEATING
(F)
SOURCE COIL
Min. Entering Liquid
50
20
Normal Entering Water
85
60
Max Entering Water
110
70
LOAD COIL
Min. Entering Water
50
60
Normal Entering Water
60
100
Max Entering Water
90
120
When the compressor is rotating in the wrong direction, the
unit makes an elevated level of noise and does not provide
cooling. Damage to compressor will occur if allowed to
operate in this manner.
UNIT
50RWS
GPM
PRESSURE DROP (psi)
30° F
50° F
70° F
90° F
036
5.0
4.2
2.6
2.3
1.8
7.0
5.8
4.1
4.1
3.1
9.0
8.4
6.0
5.5
4.9
060
7.5
3.1
2.2
1.9
1.5
11.3
5.0
4.0
3.6
3.1
15.0
7.4
6.1
5.5
5.0
120
15.0
4.3
3.1
2.7
2.1
22.6
7.0
5.6
5.0
4.3
30.0
10.3
8.5
7.7
7.0
360
45.0
2.8
2.6
2.4
2.3
67.5
5.9
5.5
5.1
4.8
90.0
10.1
9.4
8.7
8.2
UNIT
50RWS
GPM
PRESSURE DROP (psi)
30° F
50° F
70° F
90° F
036
5.0
—
2.3
1.6
1.3
7.0
—
4.1
2.9
2.6
9.0
—
5.3
4.6
4.3
060
7.5
—
1.9
1.4
1.1
11.3
—
3.4
2.9
2.2
15.0
—
5.6
4.6
3.9
120
15.0
—
2.6
2.0
1.6
22.6
—
4.8
3.9
3.1
30.0
—
7.8
6.4
5.3
360
45.0
—
2.4
2.2
2.1
67.5
—
5.2
4.8
4.5
90.0
—
8.9
8.2
7.7
To avoid possible injury or death due to electrical shock,
open the power supply disconnect switch and secure it in
an open position before flushing system. Install lockout
tag.
