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▪ Fit the heater horizontally around the crankcase, ensuring that it is in c lose c ontac t wit h t he
compressor housing along the entire length.
▪ Avoid having the heating portion of the heater in contact with any weld projection (Fig. 9 & 10).
▪ Avoid having the assembly heater inclined (Fig. 11).
▪ Close the lock and tighten the screw, torque: 2-3 Nm.
▪ The excess clamp bracket may be trimmed. Sharp edges must not come into contact with wires.
▪ The presence of the heater shall be made evident by the posting of caution signs or markings at
appropriate locations.
Figure 8
Electrical connection
▪ Connect the crankcase heater according to the compressor application guidelines.
▪ The crankcase heater must be connected only to its rated voltage.
▪ The metal braid of the heater must be connected to a suitable earthing terminal.
▪ Check the resistance according to the technical data.
▪ Perf orm an insulation test before start-up.
▪ Electrical security and safety measures are to be provided on site.
3.6
Soft starters
Sof t starters can be used with the 20 to 40 hp Copeland sc roll c ompres sors t o red uce inrush
current. Sof t starters should be selected according to the sof t starter manuf acturer's
recommendations, taking into consideration ambient temperature, number of starts per hour, and
compressor amps. The maximum ramp-up time should not exceed 3 seconds.
Due to the inherent design of the Copeland scroll, the internal compression c omponents st art
unloaded, even if system pressures are not balanced. Since the compressor internal pressures are
balanced at start-up, low voltage starting characteristics are excellent, and starting components are
normally not required.
However, f or extreme electrical conditions such as weak power supplies, single-phase soft starters
can be supplied on request by Emerson, while three-phase sof t starters are available on the
market.
3.7
Discharge gas temperature protection
CAUTION
Inadequate lubrication! Scroll set damage! Compressors ZH04K1P to
ZH19K1P and ZHI05K1P to ZHI46K1P must be equipped with a d ischarge
gas temperature protection.
A good system control shall prevent the system from operating outside t he published operat ing
envelope and acceptable superheat range, whatever the climatic conditions and the capacit y
demand. However, under some extreme operating conditions such as loss of charge o r improper
control operation, the internal discharge gas temperature reached can cause compressor damage.
In order to ensure positive compressor protection, discharge gas temperature protection is required
f or any application with Copeland compressors.
For compressors ZH04K1P to ZH19K1P the maximum discharge gas temperature is 140 °C. Fo r
compressors ZHI18K1P and ZHI23K1P single BOM 526 and ZHI05K1P to ZHI14K1P it is 135 °C.
These compressors must be equipped with an external discharge gas temperature protection – see
Figure 12. The protection shall be installed 120 mm from the compressor shell, along the st raight
or bended pipe.
12
Figure 9
Figure 10
AGL_HP_ST_ZHK1P_EN_Rev00
Figure 11
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