Piping - heat-timer VSP Installation & Operating Instructions Manual

PIPING OVERVIEW
• The Primary loop may have multiple injection loops or other takeoffs. However, the piping for each injection system
must meet the requirements described below and shown on the next page.
• The Injection piping can be installed in either a horizontal or a vertical configuration.
• The pipe diameters of the Primary and Secondary loops may differ.
• The Injection Piping diameter must be at least one pipe size smaller than the smaller of the Primary or Secondary loop
piping. For example, if the Primary loop diameter is 1 1/4" and the Secondary loop diameter is 1", then the diameter of
the Injection piping must be 3/4" or smaller. See Sizing pages 4 and 5 for actual pipe size.
CAUTION: The Injection pump and pipe sizing should be performed by a qualified engineer or
contractor.
• The Injection pump motor must be a fractional horsepower permanent split capacitor type. The Injection pump will
control the amount of water pumped from the hot Primary loop into the Secondary loop.
• A globe type valve should be installed on the injection return piping. This helps to balance the system.
• The distance between the injection tees should be as short as possible. The maximum distance between the two tees
can be no more than 4 times the pipe diameter. For instance, if the pipe diameter is 1" then the length of straight pipe
between the two injection tees can not exceed 4".
INSTALLING THE WELLS
• Two wells are supplied with the VSP. One is for the Secondary loop sensor and
one is for the Return water sensor.
• The wells should not be located more than 500' from the VSP controller.
• Both wells are 3/8" ID.
• The wells are designed to be installed in a tee with a 3/4" bull.
• Solder the well into the bull of the tee as shown. Slide the sensor into the
well after the joint has cooled.
Secondary Loop Well
• This well should be located past the pump in the Secondary loop supply.
• The sensor in this well will measure the temperature of the Secondary
loop. The VSP will control the Injection pump based on the information
from this sensor.
Boiler Return Well
• The sensor in this well will measure the temperature of the water returning to the boiler.
• If the sensor is installed, it will allow the control to reduce the demand of the Secondary loop to help speed boiler
recovery in the event of low boiler return temperatures (see Low Return pg. 13).
• The VSP can be configured to control without this sensor input (see NOTE in Low Return pg. 13). It is not necessary
to install this well if the input will not be used.
• The well should be located in the boiler return of the Primary loop after all returns.
HORIZONTAL PIPING CONFIGURATION
• The Injection piping can be installed horizontally as shown on the next page.
• The Injection supply piping should run horizontally from the Primary to the Secondary loop.
• On the Injection return piping it is necessary to install a heat trap to prevent heat from the Primary loop entering the
Secondary loop when the Injection pump is not running.
• The return piping must drop down vertically at least 18" and then rise back up vertically at least 18".
VERTICAL PIPING CONFIGURATION
• The Injection piping can be installed vertically as shown on the next page.
• The Primary loop must be at least 18" vertically above the Secondary loop.

PIPING

2
TEE
SOLDER
3/4" WELL
HT# 350147
SENSOR
HT#904015
STOP