Danfoss TGH Series Applications And Installation Manual Download

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M-AP-001-EN Rev. Q

situations such as systems with low subcooling on start or extended piping runs. A full flow filter/drier
must be installed and a liquid sight glass must be installed adjacent to each compressor. In multiple
compressor systems, a single filter/dryer may serve multiple compressors but each compressor must
have a dedicated sight glass.

13.4 Electrical Requirements

Power is permanently connected to the compressor connection terminals. A line reactor must be
connected in series with the compressor connection. The line reactor enclosure or box should be
properly ventilated to avoid overheating.

13.5 Application-Specific Requirements

13.5.1 Medium Evaporating Temperature Application (TGS230/TTH375/TGH285/TTS300)

NOTE

Medium Evaporating Temperature is defined as between 0 and -10 °C (between 32 and 14 °F) for TTS300/TGS230 and between 0
and -18°C (between 32 and -0.4 °F) for TTH375/TGH285.

1. Check the operating envelope for limits, required compressor version, and accessories.
2. For medium-temperature applications, an evaporating pressure regulator, Type KVP, is

included with the compressor and must be installed external to the compressor between
the main suction line and the motor/electronics cooling outlet port adjacent to the inter
stage port. The valve has a Solder ODF connection with 7/8" diameter ( Danfoss KVP 22), set
at a corresponding pressure to 0.8°C (34°F) saturated temperature (depending on the used
refrigerant). The motor/electronics cooling outlet port is fitted with a 5/8” flare adapter.

NOTE

Danfoss LLC highly recommends the insulation of the suction and inter-stage pipe as well as the bottom of the compressor for MT
applications to prevent ice buildups.

13.5.2 Low Lift Application

The standard TTS/TGS control limits compressor speed and capacity above a 1.5 pressure ratio to
ensure adequate motor/inverter cooling. When enabled, the low lift option is meant to enable
increased compressor speed and capacity at pressure ratios below 1.5. To ensure adequate cooling
for extended operation with pressure ratios below 1.5, the chiller system must provide the subcooled
refrigerant flow specified in "Table 13-2 Low Lift Pump Sizing". In most circumstances and system
designs, that will require the use of an OEM supplied liquid refrigerant pump. If an adequate supply
of subcooled liquid is not provided, the compressor will limit speed and capacity to maintain safe
operating temperatures. If safe temperatures cannot be maintained, the compressor will fault.
Repeated operation without adequate motor cooling could result in damage to the compressor and
evidence of such operation could limit warranty coverage.

Refer to "Figure 14-1 Typical Refrigeration Piping Schematic" on page 65 for a possible pump design
and "Table 13-2 Low Lift Pump Sizing" for pump sizing. Though each OEM may choose to use more
sophisticated logic, a simplified control logic would turn the pump on at pressure ratios below 1.5
and off when the pressure ratio rises to 1.7. By default, the low lift option is not enabled. More details
on enabling the low lift option and the alarm and faults associated with it are included in the

OEM

Programming Manual.