National Lab PCGE Series, Operating And Maintenance Manual

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9) Make sure that the oil is able to circulate adequately. It the circuit might be interrupted by something such as a valve,
electrical valve, a filter or anything else, a by-pass circuit (automatic overflow valve) must be installed in order to pre-
vent damage to the pump.
10) Lock the switch cabinet with the key.
11) Move the main switch of the chiller to position ” 1 ’ (the temperature of the cooling medium is displayed).
Never touch any part of the refrigeration circuit when the chiller is running!
12) Start up the compressor by pressing the button for 3 seconds.
13) Wait until the chiller has attained the operating conditions. This is indicated when the display shows the preset working
range.
14) Because the pump starts up immediately, make sure that the direction of rotation for the pump matches the direction of
the arrow on the casing. If it is rotating in the opposite direction, turn off the main switch of the chiller immediately and
arrange for the polarity of the chiller to be reversed.
15) After a few minutes carefully open the filler screw again in order to remove any residual air. Tighten the screw again af-
terwards.
16) Check whether the pressure shown is within the limits specified for the pump. If not, take appropriate action to ensure
that pump is able to run within the specified limits.
17) Wait for the compressor to switch on. The compressor symbol will appear on the display (see Section 6.4).
18) Check the inside of the chiller and the piping system for leakage or loose connections.
19) Fit the front panel and the two side panels back onto the casing.
20) The chiller is normally factory-set to the temperature required by the customer.
21) When the chiller is within the operating conditions set by the manufacturer, check whether the current uptake of the
chiller matches the data indicated on the identification plate and those contained in the table in the supplement.
6.3 CHECK LIST FOR COMMISSIONING GLYCOL RECIRCULATING CHILLERS
After turning off the main switch for more than 1 hour or after extraordinary maintenance work, each chiller start
should be regarded as an initial start-up.
The initial start-up calls for a number additional checks to ensure safe and reliable performance of the system.
6.3.1 REQUIREMENTS FOR THE WATER-GLYCOL MIXTURE
Quality:
A water-glycol mixture should be used for filling the chiller (glycol = ethylene glycol). Corrosion-inhibiting additives
may also be included provided they are explicitly authorized for this purpose by the manufacturer concerned. The
glycol content must be at least 20% and should not exceed 25%.
Cold water discharge temperature Ethylene glycol in %
Ä 0 ± C
- 5 ± C
- 10 ± C
20
20
25
General operating conditions:
The glycol recirculating chiller is designed for cooling medium temperatures of -10 ± C to Ä 0 ± C.
Conditions during commissioning:
Should liquid temperatures different to those described in the general operating conditions occur during the initial
start-up, be sure to contact the manufacturer.
6.3.2 CHECKLIST FOR PCGEZ 08 TO PCGEZ 480
Controller Type ” A Ü , see 6.4 (PCGEZ 08)
1) Remove the upper lid panel and the two side panels.
2) Open the tank cap and fill the tank (using a T-fitting if necessary) while watching the level indicator (refer to Fig. 1, Point
5.2.1).
3) Open the filler screw on the pump head.
4) Tighten the screw again when only cooling medium flows out.
5) Open the shut-off valve.
6) Move the main switch of the chiller to position ” 1 ’ (the display will show ” OFF ’ , and the pump will start to run).
7) Top up the tank again if too much cooling medium has flowed out of the shut-off valve. Fasten the tank cap again after-
wards.
8) After a few minutes carefully open the filler screw again in order to remove any residual air. Tighten the screw again af-
terwards.
9) Replace the upper lid panel and the two side panels.
10) Start up the compressor by pressing the button for 3 seconds.
11) Wait until the chiller has attained the operating conditions. This is indicated when the actual temperature shown in the
display matches the preset target temperature.
12) When the chiller is within the operating conditions set by the manufacturer, check whether the current uptake of the
chiller matches the data indicated on the identification plate and those contained in the table in the supplement.