T Based Control; Technical Specifications - Grundfos Geo-Flo Universal Pump Controller Installation, Operating And Maintenance Manual

2 | Installation, Operating, and Maintenance Manual
ΔT based control (Two immersion thermistors required)
The UPC-GEO receives a 24VAC signal from the heat pump or thermostat for heating or cooling. The UPC-GEO
then provides a PWM signal to the Magna GEO 32-140 pump (or 0-10 VDC output for other pumps) and moni-
tors the temperatures provided from the EWT and LWT thermistors and the return signal from the pump. The
UPC-GEO drives the pump at 90% for two minutes before increasing or decreasing the pump speed based on
the delta-T (ΔT) set point for heating or cooling mode and the actual ΔT of the system. The controller recog-
nizes whether the heat pump is in heating or cooling mode by monitoring the EWT and LWT temperatures (i.e.
heating mode: LWT<EWT; cooling mode: LWT>EWT). For higher flow rate and/or head loss systems a two-pump
variable speed flow center system may be required. This flow center consists of a single variable speed Magna
GEO 32-140 and a constant speed UPS26-99. The UPC-GEO attempts to satisfy the ΔT requirement by first using
the more efficient Magna GEO 32-140 pump. If the Magna GEO reaches its maximum performance level before
satisfying the ΔT set point requirement, the UPC-GEO energizes the UPS26-99 and ramps the Magna GEO down
to match the requirement thereby minimizing pumping power.

Technical Specifications

Parameter
Input Voltage
Input Frequency
PWM Input Frequency
PWM Input Voltage
PWM Output Frequency
PWM Output Voltage*
0-10 VDC Output Voltage*
Thermistor Input
HP IN1
HP IN2
1-10 VDC input
GND
L1/N1 (input for second pump)
L2/N2 (output for second pump)
Relay for L1/N1 to L2/N2
Display
DB9 connector (serial communication) N/A
Nominal power consumption
*Default controller output is PWM. Alternate 0-10 VDC output may be selected in the controller menu for Flow
mode or ∆T mode.
Rating
24 VAC, 200 mA Max
60 Hz
75 Hz
Open Collector
3.9 kHz
12 VDC
1 to 10 VDC
NTC 10k
24 VAC or dry contact across terminals
24 VAC or dry contact across terminals
Not currently used
Earth Ground Connection
120/208-230 VAC
120/208-230 VAC
4A Max
128 x 64 pixels
3.5 VA
Rev. 05JUL2016
Tolerance (+/-)
10%
20%
10%
n/a
10%
10%
10%
N/A
10% (for 24 VAC Input)
10% (for 24 VAC Input)
N/A
N/A
10%
10%
N/A
N/A
N/A