Crestline VFD Specification / NEMA MG-1 Part 31

Crestline Valve Specification / MSS SP-110

These ball valves meet all specification requirements for 2-inch and smaller service. The 600 PSI rating meets the requirement for ball valves 2 inches and smaller. Full-port design ensures minimal pressure drop and allows full flow capacity — a reduced port valve would restrict flow and create an unacceptable pressure drop. The PTFE (Teflon) seat material provides excellent chemical resistance, low friction, and is compatible with chilled water temperatures. The 600 PSI rating at 42°F operating temperature provides substantial safety margin over the 125 PSI system pressure.

Crestline VFD Specification

The 25-foot cable run exceeds the 20-foot maximum allowed without engineer approval. Long VFD output cables cause reflected wave voltage spikes at the motor terminals that can reach 2-3 times the DC bus voltage, destroying motor winding insulation over time. At 25 feet without mitigation, peak voltage at the motor terminals can exceed the insulation rating of standard motors. The electrician must either: (1) get engineer approval and install an output reactor or dV/dt filter, (2) relocate the VFD closer to the motor, or (3) use an inverter-duty motor rated for the higher voltage peaks.

Crestline VFD Specification / IEEE 519

The 8 kHz carrier frequency is within the allowable range. The specification requires starting at 2 kHz minimum with a maximum of 10 kHz. Higher carrier frequencies reduce audible motor noise (the whining sound) but increase heat generation in the VFD and can increase cable stress. At 8 kHz, this is an acceptable tradeoff for noise-sensitive areas. The electrician should verify the VFD's thermal derating at this frequency and ensure adequate ventilation of the VFD enclosure.

Crestline VFD Specification / NFPA 70

At 15 feet, the cable length is within the 20-foot maximum allowed without engineer approval. Short cable runs minimize reflected wave voltage spikes that can damage motor winding insulation. VFD output pulses travel along the cable and reflect at the motor terminals — longer cables create higher voltage peaks. The proper shielded cable and correct shield grounding at both ends also helps contain electromagnetic interference (EMI). If the run needed to exceed 20 feet, an output reactor or dV/dt filter would be required.

EJMA Standards / ASME B31.1 Section 119

Bellows expansion joints require pipe guides on both sides to ensure axial movement only. Without guides, lateral forces can distort the bellows and cause premature failure.

EJMA Standards / Manufacturer Installation Guide

Shipping restraint bars/rods must be removed after installation and before system operation. Leaving them in prevents the joint from absorbing expansion, transferring all stress to anchors and equipment.