Operating instructions
56 IMM AGSB-60
Start-up After Extended (Seasonal) Shutdown
1. With all electrical disconnects locked and tagged open, check all screw or lug-type
electrical connections to be sure they are tight for good electrical contact.
2. Check the voltage of the unit power supply and see that it is within the ±10% tolerance
that is allowed. Voltage unbalance between phases must be within ±2%.
3. See that all auxiliary control equipment is operative and that an adequate cooling load is
available for start-up.
4. Check all compressor flange connections for tightness to avoid refrigerant loss. Always
replace valve seal caps.
5. Make sure system switch S1 is in the off position and circuit pumpdown switches, CS, are
set to the off position. Place the main power and control disconnect switches to on. This
will energize the crankcase heaters. Wait a minimum of 12 hours before starting up unit.
Turn compressor circuit breakers to "off" position until ready to start unit.
6. Open the optional compressor suction butterfly as well as the liquid line shutoff valves.
7. Vent the air from the evaporator water side as well as from the system piping. Open all
water flow valves and start the chilled water pump. Check all piping for leaks and recheck
for air in the system. Verify the correct flow rate by taking the pressure drop across the
evaporator and checking the pressure drop curves in the installation manual, IMM AGS
8. The following table gives glycol concentrations required for freeze protection.
Table 30, Freeze Protection
Percent Volume Glycol Concentration Required
For Freeze Protection For Burst Protection
Temperature
°F (°C)
Ethylene Glycol Propylene Glycol Ethylene Glycol Propylene Glycol
20 (6.7) 16 18 11 12
10 (-12.2) 25 29 17 20
0 (-17.8) 33 36 22 24
-10 (-23.3) 39 42 26 28
-20 (-28.9) 44 46 30 30
-30 (-34.4) 48 50 30 33
-40 (-40.0) 52 54 30 35
-50 (-45.6) 56 57 30 35
-60 (-51.1) 60 60 30 35
Notes:
1. These figures are examples only and cannot be appropriate to every situation. Generally, for an extended margin of
protection, select a temperature at least 10
°F lower than the expected lowest ambient temperature. Inhibitor levels
should be adjusted for solutions less than 25% glycol.
2. Glycol of less than 25% concentration is not recommended because of the potential for bacterial growth and loss of heat
transfer efficiency.